nature vs nurture essay plan

Nature versus Nurture: the Simple Contrast Essay

Introduction, historical background of nature and nurture debate, the impact of charles darwin’s natural selection theory on the debate, francis galton’s position on nature versus nurture debate, the neutrality of darwin’s theory, reference list.

The relationship between nature and nurture has constantly raised controversial debates about the roles of the two factors in heredity and external behavior of a person. As a result, there has been confusion about the functions of nature and nurture in shaping human personality. Some psychologists have shown strong support for nature as a crucial factor that shapes human behavior due to genetic inheritance. However, other psychologists believe that nurture is responsible for the development of personality. This essay explores the nature and nurtures debate in an attempt to provide an insight into the factors that shape the personality of a person.

Nature and nurture debate has been going on for centuries. However, Francis Galton is deemed responsible for coining the nature versus nurture debate in 1869 (Stiles, 2011). Since then, psychologists have engaged in many studies to establish the role of nature and nurture in shaping the characters of individuals. Each side of the debate has brought forth substantial evidence to support their arguments.

The availability of evidence to support each side of the debate has almost resulted in an impossibility to reach a consensus. As a result, the question of the roles of nature and nurture in the determination of human behavior has remained a dilemma amongst psychologists. Scientists are still pondering on the subject by employing the latest technological proficiency to study the impact of nature and nurture on people in an attempt to establish how the two factors influence personality traits.

In the context of this essay, nature signifies the effect of genes in the DNA structure that are transferable from a parent to the offspring. The nativists, who are the proponents of nature, base their argument on the fact that behavior and personality are transferred to the offspring through the same biological principles (Stiles, 2011). Nurture is used to describe the conditions that characterize the environment in which a person grows. The kind of experiences that people go through since their birth has significant effects on personality traits. The empiricists, who are the proponents of nurture, believe that a person is born with a blank slate or tabula rasa. Eventually, different experiences fill the tabula rasa with diverse knowledge.

Charles Darwin is a great psychologist who is recognized for his famous work on the evolution theory. In his popular ‘survival for the fittest’ ideology, Darwin categorically pointed out that any creature must adapt to the changing environment to survive (Davidoff, Goldstein, & Roberson, 2009). In 1871, he developed an explanation of the emotional expressions in both man and animals based on evolution. In this context, expressions refer to the behaviors that are expressed by human beings that can be attributed to evolutionary biology. Evolutionary biology is the study of how evolution has brought about changes in the lives of human beings. It explains the parent-child evolutionary characteristics that make them assume resembling or dissimilar traits.

Darwin’s theory of natural selection upholds that some of the most suitable traits to bring about adaptation to the next generation are more transferable through inheritance than maladaptive features. From the genetic composition of the two parents, the most adaptive features are chosen to make up the offspring (Davidoff et al., 2009). This situation makes the offspring assume slight personality differences from those of the parents. Exclusively, different traits are bound to appear in the behavior of future generations due to the accumulation of minute differences over time.

The interventions of the natural selection theory have influenced the works of many psychologists. This situation has led to many questions about how much the selection is possible for adaptation. The natural selection theory holds that blind mutation is responsible for personality. According to Stiles (2011), this ideology supports that nature is a part of the factors that determine the personality characteristics of an individual.

A cousin of Darwin, Francis Galton, was impressed by the natural selection theory. This situation compelled him to pursue numerous studies to establish the role of nature and nurture in shaping personality traits, especially on the eminent people who lived in England at the time. He focused on the study of heredity and concluded that nature always prevailed enormously over nurture. His stand can be deduced from his innate views and nativism influences.

For instance, the two famous Indian feral sisters who were brought up by a wolf walked on fours and had a very sharp sense of sight, smell, and hearing (Goldhaber, 2012). Astonishingly, the feral sisters ate their food like the wolf and preferred fresh raw meat. This behavior is not ordinary in human society. The above examples have supported the development of a new school of thought, which holds that nature and nurture determine the character of a person independently.

Darwin’s theory of natural selection proves that nature assumes a vital role in the development of personality through evolutionary biology (Stiles, 2011). However, Darwin posits that human behavior is prone to change due to competition pressure. The reasoning is a product of intelligence that determines the way in which a person is nurtured by the surrounding environment. Both views in the Darwinism approach make his theory dualistic; hence, it is neutral to the debate. This situation makes the theory irrelevant in solving the nature versus nurture dilemma.

According to Goldhaber (2012), the controversial debate has compelled many psychologists to accept that both nature and nurture play special roles in personality creation. For instance, the behavior of direct twins who are separated immediately after birth is almost the same regardless of their exposure to different environments. This situation implies that their character is a product of genetic inheritance. On the other side, feral children have undoubtedly shown that life experiences that are acquired as a person grows are directly correlated with the kind of behavior they exhibit.

The nature versus nature debate cannot be solved easily. Empiricists such as Skinner, who managed to condition the behavior of pigeons and dogs have shown that nurture is crucial in shaping the personality of a person. Elsewhere, other psychologists in the twin study case have shown that nature plays a very crucial function in personality development. Galton proved that the powerful traits in geniuses are traceable through the family tree. His theory supports that heredity is responsible for the personality traits of an individual. Genes that are transferred to the offspring carry with them hereditary personality traits. Nonetheless, the environment in which a person lives leads to the adoption of other traits through reasoning.

Davidoff, J., Goldstein, J., & Roberson, D. (2009). Nature versus Nurture: The Simple Contrast. Journal of Experimental Child Psychology , 102 (2), 246-50.

Goldhaber, D. (2012). The Nature-nurture Debate: Bridging the Gap . Cambridge: Cambridge University Press.

Stiles, J. (2011). Brain development and the nature versus nurture debate. Progress in Brain, 189 (1), 3-22.

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Nature vs. Nurture Debate In Psychology

Saul Mcleod, PhD

Editor-in-Chief for Simply Psychology

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Saul Mcleod, PhD., is a qualified psychology teacher with over 18 years of experience in further and higher education. He has been published in peer-reviewed journals, including the Journal of Clinical Psychology.

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The nature vs. nurture debate in psychology concerns the relative importance of an individual’s innate qualities (nature) versus personal experiences (nurture) in determining or causing individual differences in physical and behavioral traits. While early theories favored one factor over the other, contemporary views recognize a complex interplay between genes and environment in shaping behavior and development.

Key Takeaways

• Nature is what we think of as pre-wiring and is influenced by genetic inheritance and other biological factors.
• Nurture is generally taken as the influence of external factors after conception, e.g., the product of exposure, life experiences, and learning on an individual.
• Behavioral genetics has enabled psychology to quantify the relative contribution of nature and nurture concerning specific psychological traits.
• Instead of defending extreme nativist or nurturist views, most psychological researchers are now interested in investigating how nature and nurture interact in a host of qualitatively different ways.
• For example, epigenetics is an emerging area of research that shows how environmental influences affect the expression of genes.

The nature-nurture debate is concerned with the relative contribution that both influences make to human behavior, such as personality, cognitive traits, temperament and psychopathology.

Examples of Nature vs. Nurture

Nature vs. nurture in child development.

In child development, the nature vs. nurture debate is evident in the study of language acquisition . Researchers like Chomsky (1957) argue that humans are born with an innate capacity for language (nature), known as universal grammar, suggesting that genetics play a significant role in language development.

Conversely, the behaviorist perspective, exemplified by Skinner (1957), emphasizes the role of environmental reinforcement and learning (nurture) in language acquisition.

Twin studies have provided valuable insights into this debate, demonstrating that identical twins raised apart may share linguistic similarities despite different environments, suggesting a strong genetic influence (Bouchard, 1979)

However, environmental factors, such as exposure to language-rich environments, also play a crucial role in language development, highlighting the intricate interplay between nature and nurture in child development.

Nature vs. Nurture in Personality Development

The nature vs. nurture debate in personality psychology centers on the origins of personality traits. Twin studies have shown that identical twins reared apart tend to have more similar personalities than fraternal twins, indicating a genetic component to personality (Bouchard, 1994).

However, environmental factors, such as parenting styles, cultural influences, and life experiences, also shape personality.

For example, research by Caspi et al. (2003) demonstrated that a particular gene (MAOA) can interact with childhood maltreatment to increase the risk of aggressive behavior in adulthood.

This highlights that genetic predispositions and environmental factors contribute to personality development, and their interaction is complex and multifaceted.

Nature vs. Nurture in Mental Illness Development

The nature vs. nurture debate in mental health explores the etiology of depression. Genetic studies have identified specific genes associated with an increased vulnerability to depression, indicating a genetic component (Sullivan et al., 2000).

However, environmental factors, such as adverse life events and chronic stress during childhood, also play a significant role in the development of depressive disorders (Dube et al.., 2002; Keller et al., 2007)

The diathesis-stress model posits that individuals inherit a genetic predisposition (diathesis) to a disorder, which is then activated or exacerbated by environmental stressors (Monroe & Simons, 1991).

This model illustrates how nature and nurture interact to influence mental health outcomes.

Nature vs. Nurture of Intelligence

The nature vs. nurture debate in intelligence examines the relative contributions of genetic and environmental factors to cognitive abilities.

Intelligence is highly heritable, with about 50% of variance in IQ attributed to genetic factors, based on studies of twins, adoptees, and families (Plomin & Spinath, 2004).

Heritability of intelligence increases with age, from about 20% in infancy to as high as 80% in adulthood, suggesting amplifying effects of genes over time.

However, environmental influences, such as access to quality education and stimulating environments, also significantly impact intelligence.

Shared environmental influences like family background are more influential in childhood, whereas non-shared experiences are more important later in life.

Research by Flynn (1987) showed that average IQ scores have increased over generations, suggesting that environmental improvements, known as the Flynn effect , can lead to substantial gains in cognitive abilities.

Molecular genetics provides tools to identify specific genes and understand their pathways and interactions. However, progress has been slow for complex traits like intelligence. Identified genes have small effect sizes (Plomin & Spinath, 2004).

Overall, intelligence results from complex interplay between genes and environment over development. Molecular genetics offers promise to clarify these mechanisms. The nature vs nurture debate is outdated – both play key roles.

Nativism (Extreme Nature Position)

It has long been known that certain physical characteristics are biologically determined by genetic inheritance.

Color of eyes, straight or curly hair, pigmentation of the skin, and certain diseases (such as Huntingdon’s chorea) are all a function of the genes we inherit.

These facts have led many to speculate as to whether psychological characteristics such as behavioral tendencies, personality attributes, and mental abilities are also “wired in” before we are even born.

Those who adopt an extreme hereditary position are known as nativists.  Their basic assumption is that the characteristics of the human species as a whole are a product of evolution and that individual differences are due to each person’s unique genetic code.

In general, the earlier a particular ability appears, the more likely it is to be under the influence of genetic factors. Estimates of genetic influence are called heritability.

Examples of extreme nature positions in psychology include Chomsky (1965), who proposed language is gained through the use of an innate language acquisition device. Another example of nature is Freud’s theory of aggression as being an innate drive (called Thanatos).

Characteristics and differences that are not observable at birth, but which emerge later in life, are regarded as the product of maturation. That is to say, we all have an inner “biological clock” which switches on (or off) types of behavior in a pre-programmed way.

The classic example of the way this affects our physical development are the bodily changes that occur in early adolescence at puberty.

However, nativists also argue that maturation governs the emergence of attachment in infancy , language acquisition , and even cognitive development .

Empiricism (Extreme Nurture Position)

At the other end of the spectrum are the environmentalists – also known as empiricists (not to be confused with the other empirical/scientific  approach ).

Their basic assumption is that at birth, the human mind is a tabula rasa (a blank slate) and that this is gradually “filled” as a result of experience (e.g., behaviorism ).

From this point of view, psychological characteristics and behavioral differences that emerge through infancy and childhood are the results of learning.  It is how you are brought up (nurture) that governs the psychologically significant aspects of child development and the concept of maturation applies only to the biological.

For example, Bandura’s (1977) social learning theory states that aggression is learned from the environment through observation and imitation. This is seen in his famous bobo doll experiment (Bandura, 1961).

Also, Skinner (1957) believed that language is learned from other people via behavior-shaping techniques.

Evidence for Nature

• Biological Approach
• Biology of Gender
• Medical Model

Freud (1905) stated that events in our childhood have a great influence on our adult lives, shaping our personality.

He thought that parenting is of primary importance to a child’s development , and the family as the most important feature of nurture was a common theme throughout twentieth-century psychology (which was dominated by environmentalists’ theories).

Behavioral Genetics

Researchers in the field of behavioral genetics study variation in behavior as it is affected by genes, which are the units of heredity passed down from parents to offspring.

“We now know that DNA differences are the major systematic source of psychological differences between us. Environmental effects are important but what we have learned in recent years is that they are mostly random – unsystematic and unstable – which means that we cannot do much about them.” Plomin (2018, xii)

Behavioral genetics has enabled psychology to quantify the relative contribution of nature and nurture with regard to specific psychological traits. One way to do this is to study relatives who share the same genes (nature) but a different environment (nurture). Adoption acts as a natural experiment which allows researchers to do this.

Empirical studies have consistently shown that adoptive children show greater resemblance to their biological parents, rather than their adoptive, or environmental parents (Plomin & DeFries, 1983; 1985).

Another way of studying heredity is by comparing the behavior of twins, who can either be identical (sharing the same genes) or non-identical (sharing 50% of genes). Like adoption studies, twin studies support the first rule of behavior genetics; that psychological traits are extremely heritable, about 50% on average.

The Twins in Early Development Study (TEDS) revealed correlations between twins on a range of behavioral traits, such as personality (empathy and hyperactivity) and components of reading such as phonetics (Haworth, Davis, Plomin, 2013; Oliver & Plomin, 2007; Trouton, Spinath, & Plomin, 2002).

Implications

Jenson (1969) found that the average I.Q. scores of black Americans were significantly lower than whites he went on to argue that genetic factors were mainly responsible – even going so far as to suggest that intelligence is 80% inherited.

The storm of controversy that developed around Jenson’s claims was not mainly due to logical and empirical weaknesses in his argument. It was more to do with the social and political implications that are often drawn from research that claims to demonstrate natural inequalities between social groups.

For many environmentalists, there is a barely disguised right-wing agenda behind the work of the behavioral geneticists.  In their view, part of the difference in the I.Q. scores of different ethnic groups are due to inbuilt biases in the methods of testing.

More fundamentally, they believe that differences in intellectual ability are a product of social inequalities in access to material resources and opportunities.  To put it simply children brought up in the ghetto tend to score lower on tests because they are denied the same life chances as more privileged members of society.

Now we can see why the nature-nurture debate has become such a hotly contested issue.  What begins as an attempt to understand the causes of behavioral differences often develops into a politically motivated dispute about distributive justice and power in society.

What’s more, this doesn’t only apply to the debate over I.Q.  It is equally relevant to the psychology of sex and gender , where the question of how much of the (alleged) differences in male and female behavior is due to biology and how much to culture is just as controversial.

Polygenic Inheritance

Rather than the presence or absence of single genes being the determining factor that accounts for psychological traits, behavioral genetics has demonstrated that multiple genes – often thousands, collectively contribute to specific behaviors.

Thus, psychological traits follow a polygenic mode of inheritance (as opposed to being determined by a single gene). Depression is a good example of a polygenic trait, which is thought to be influenced by around 1000 genes (Plomin, 2018).

This means a person with a lower number of these genes (under 500) would have a lower risk of experiencing depression than someone with a higher number.

The Nature of Nurture

Nurture assumes that correlations between environmental factors and psychological outcomes are caused environmentally. For example, how much parents read with their children and how well children learn to read appear to be related. Other examples include environmental stress and its effect on depression.

However, behavioral genetics argues that what look like environmental effects are to a large extent really a reflection of genetic differences (Plomin & Bergeman, 1991).

People select, modify and create environments correlated with their genetic disposition. This means that what sometimes appears to be an environmental influence (nurture) is a genetic influence (nature).

So, children that are genetically predisposed to be competent readers, will be happy to listen to their parents read them stories, and be more likely to encourage this interaction.

Interaction Effects

However, in recent years there has been a growing realization that the question of “how much” behavior is due to heredity and “how much” to the environment may itself be the wrong question.

Take intelligence as an example. Like almost all types of human behavior, it is a complex, many-sided phenomenon which reveals itself (or not!) in a great variety of ways.

The “how much” question assumes that psychological traits can all be expressed numerically and that the issue can be resolved in a quantitative manner.

Heritability statistics revealed by behavioral genetic studies have been criticized as meaningless, mainly because biologists have established that genes cannot influence development independently of environmental factors; genetic and nongenetic factors always cooperate to build traits. The reality is that nature and culture interact in a host of qualitatively different ways (Gottlieb, 2007; Johnston & Edwards, 2002).

Instead of defending extreme nativist or nurturist views, most psychological researchers are now interested in investigating how nature and nurture interact.

For example, in psychopathology , this means that both a genetic predisposition and an appropriate environmental trigger are required for a mental disorder to develop. For example, epigenetics state that environmental influences affect the expression of genes.

What is Epigenetics?

Epigenetics is the term used to describe inheritance by mechanisms other than through the DNA sequence of genes. For example, features of a person’s physical and social environment can effect which genes are switched-on, or “expressed”, rather than the DNA sequence of the genes themselves.

Stressors and memories can be passed through small RNA molecules to multiple generations of offspring in ways that meaningfully affect their behavior.

One such example is what is known as the Dutch Hunger Winter, during last year of the Second World War. What they found was that children who were in the womb during the famine experienced a life-long increase in their chances of developing various health problems compared to children conceived after the famine.

Epigenetic effects can sometimes be passed from one generation to the next, although the effects only seem to last for a few generations. There is some evidence that the effects of the Dutch Hunger Winter affected grandchildren of women who were pregnant during the famine.

Therefore, it makes more sense to say that the difference between two people’s behavior is mostly due to hereditary factors or mostly due to environmental factors.

This realization is especially important given the recent advances in genetics, such as polygenic testing.  The Human Genome Project, for example, has stimulated enormous interest in tracing types of behavior to particular strands of DNA located on specific chromosomes.

If these advances are not to be abused, then there will need to be a more general understanding of the fact that biology interacts with both the cultural context and the personal choices that people make about how they want to live their lives.

There is no neat and simple way of unraveling these qualitatively different and reciprocal influences on human behavior.

Epigenetics: Licking Rat Pups

Michael Meaney and his colleagues at McGill University in Montreal, Canada conducted the landmark epigenetic study on mother rats licking and grooming their pups.

This research found that the amount of licking and grooming received by rat pups during their early life could alter their epigenetic marks and influence their stress responses in adulthood.

Pups that received high levels of maternal care (i.e., more licking and grooming) had a reduced stress response compared to those that received low levels of maternal care.

Meaney’s work with rat maternal behavior and its epigenetic effects has provided significant insights into the understanding of early-life experiences, gene expression, and adult behavior.

It underscores the importance of the early-life environment and its long-term impacts on an individual’s mental health and stress resilience.

Epigenetics: The Agouti Mouse Study

Waterland and Jirtle’s 2003 study on the Agouti mouse is another foundational work in the field of epigenetics that demonstrated how nutritional factors during early development can result in epigenetic changes that have long-lasting effects on phenotype.

In this study, they focused on a specific gene in mice called the Agouti viable yellow (A^vy) gene. Mice with this gene can express a range of coat colors, from yellow to mottled to brown.

This variation in coat color is related to the methylation status of the A^vy gene: higher methylation is associated with the brown coat, and lower methylation with the yellow coat.

Importantly, the coat color is also associated with health outcomes, with yellow mice being more prone to obesity, diabetes, and tumorigenesis compared to brown mice.

Waterland and Jirtle set out to investigate whether maternal diet, specifically supplementation with methyl donors like folic acid, choline, betaine, and vitamin B12, during pregnancy could influence the methylation status of the A^vy gene in offspring.

Key findings from the study include:

Dietary Influence : When pregnant mice were fed a diet supplemented with methyl donors, their offspring had an increased likelihood of having the brown coat color. This indicated that the supplemented diet led to an increased methylation of the A^vy gene.

Health Outcomes : Along with the coat color change, these mice also had reduced risks of obesity and other health issues associated with the yellow phenotype.

Transgenerational Effects : The study showed that nutritional interventions could have effects that extend beyond the individual, affecting the phenotype of the offspring.

The implications of this research are profound. It highlights how maternal nutrition during critical developmental periods can have lasting effects on offspring through epigenetic modifications, potentially affecting health outcomes much later in life.

The study also offers insights into how dietary and environmental factors might contribute to disease susceptibility in humans.

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Flynn, J. R. (1987). Massive IQ gains in 14 nations: What IQ tests really measure.  Psychological Bulletin ,  101 (2), 171.

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Further Information

• Genetic & Environmental Influences on Human Psychological Differences

Evidence for Nurture

• Classical Conditioning
• Little Albert Experiment
• Operant Conditioning
• Behaviorism
• Social Learning Theory
• Bronfenbrenner’s Ecological Systems Theory
• Social Roles
• Attachment Styles
• The Hidden Links Between Mental Disorders
• Visual Cliff Experiment
• Behavioral Genetics, Genetics, and Epigenetics
• Epigenetics
• Is Epigenetics Inherited?
• Physiological Psychology
• Bowlby’s Maternal Deprivation Hypothesis
• So is it nature not nurture after all?

Evidence for an Interaction

• Genes, Interactions, and the Development of Behavior
• Agouti Mouse Study
• Biological Psychology

What does nature refer to in the nature vs. nurture debate?

In the nature vs. nurture debate, “nature” refers to the influence of genetics, innate qualities, and biological factors on human development, behavior, and traits. It emphasizes the role of hereditary factors in shaping who we are.

What does nurture refer to in the nature vs. nurture debate?

In the nature vs. nurture debate, “nurture” refers to the influence of the environment, upbringing, experiences, and social factors on human development, behavior, and traits. It emphasizes the role of external factors in shaping who we are.

Why is it important to determine the contribution of heredity (nature) and environment (nurture) in human development?

Determining the contribution of heredity and environment in human development is crucial for understanding the complex interplay between genetic factors and environmental influences. It helps identify the relative significance of each factor, informing interventions, policies, and strategies to optimize human potential and address developmental challenges.

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Issues & Debates: Evaluating the Nature-Nurture Debate - Interactionist Approach

Last updated 22 Mar 2021

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Recently psychologists have begun to question whether human behaviour is due to heredity factors (nature) or the environment (nurture). It is now widely accepted that heredity and the environment do not act independently and both nature and nurture are essential for almost all behaviour. Therefore, instead of defending extreme nativist or environmentalist views, most researchers are now interested in investigating the ways in which nature and nurture interact. The interactionist approach is the view that both nature and nurture work together to shape human behaviour.

The interactionist approach is best illustrated by the genetic disorder PKU (phenylketonuria) . PKU is caused by the inheritance of two recessive genes, one from each parent. People with PKU are unable to break down the amino acid phenylalanine which builds up in the blood and brain causing mental retardation. However, if the child is diagnosed early, they are placed on a low protein diet for the first 12 years, which helps to avert this potentially lifelong disorder. Therefore, the disorder PKU (nature) is not expressed, because of an altered environment (low protein diet – nurture).

In psychopathology, many psychologists argue that both a genetic predisposition and an appropriate environmental trigger are required for a psychological disorder to develop; this is set out in the diathesis-stress model . The diathesis is the biological vulnerability such as being born with a gene that predisposes you to develop a disorder. However, the disorder will only develop if there is an environmental ‘stressor’ to trigger it. Evidence to support the diathesis-stress model comes from the Finnish Adoption Study w which compared 155 adopted children whose biological mothers had schizophrenia, with a matched group of children with no family history of schizophrenia. The researchers also assessed the quality of parenting through questionnaires and interviews. They found that the group with schizophrenic mothers had a 10% rate of schizophrenia, but they also discovered that all of the reported cases of schizophrenia occurred in families rated as ‘disturbed’. When the family environment was rated as ‘healthy’, even in the high-risk sample (mother with Schizophrenia), the occurrence of schizophrenia was well below the general population rates. However, the environment was not the sole cause, as the low-risk children from ‘disturbed’ families did not develop Schizophrenia – so the environment alone was not enough to trigger the disorder. This research provides strong evidence that schizophrenia is best explained by looking at an interaction between genetic inheritance and environmental triggers, in this case, family environment.

Neural plasticity is another example of how nature and nurture interact. The brain can reorganise itself by forming new neural connections throughout life. Neuroplasticity is a term which describes the changes in the structure of the brain (nature), as a result of life experience (nurture). For example, Maguire et al. (2000) investigated the hippocampi volume of London taxi drivers’ brains. She found that this region of the brain was larger in taxi drivers in comparison to non-taxi drivers. Consequently, Maguire concluded that driving a taxi (nurture) actually had an effect on the size of the hippocampi (nature).

Nature and nurture can interact in a variety of ways, and three separate types of gene-environment interactions have been described by Plomin et al. (1977) : passive, evocative/reactive, and active.

• In passive gene-environment interaction , parents pass on genes and also provide an environment, both of which influence the child’s development. For example, highly intelligent parents are likely to pass on genes for intelligence to their children. They are also more likely to provide high levels of cognitive stimulation and a good education. These correlated genetic and environmental influences both increase the likelihood that their child will be highly intelligent.
• In evocative gene-environment interaction , heritable traits influence the reaction of others and hence the environment provided by others. For example, a shy child (partly genetically influenced) may be less fun to other children, making other children less likely to want to spend time with him or her. This environment may result in the child becoming even more socially withdrawn.
• In active gene-environment interaction , a child’s heritable traits influence his or her choice of environment. For example, an aggressive child may choose to watch violent films and engage in contact sports. This is known as ‘niche-picking’ and is one reason research has shown that the influence of genes increases as children get older.

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Article contents

Nature and nurture as an enduring tension in the history of psychology.

• Hunter Honeycutt Hunter Honeycutt Bridgewater College, Department of Psychology
• https://doi.org/10.1093/acrefore/9780190236557.013.518
• Published online: 30 September 2019

Nature–nurture is a dichotomous way of thinking about the origins of human (and animal) behavior and development, where “nature” refers to native, inborn, causal factors that function independently of, or prior to, the experiences (“nurture”) of the organism. In psychology during the 19th century, nature-nurture debates were voiced in the language of instinct versus learning. In the first decades of the 20th century, it was widely assumed that that humans and animals entered the world with a fixed set of inborn instincts. But in the 1920s and again in the 1950s, the validity of instinct as a scientific construct was challenged on conceptual and empirical grounds. As a result, most psychologists abandoned using the term instinct but they did not abandon the validity of distinguishing between nature versus nurture. In place of instinct, many psychologists made a semantic shift to using terms like innate knowledge, biological maturation, and/or hereditary/genetic effects on development, all of which extend well into the 21st century. Still, for some psychologists, the earlier critiques of the instinct concept remain just as relevant to these more modern usages.

The tension in nature-nurture debates is commonly eased by claiming that explanations of behavior must involve reference to both nature-based and nurture-based causes. However, for some psychologists there is a growing pressure to see the nature–nurture dichotomy as oversimplifying the development of behavior patterns. The division is seen as both arbitrary and counterproductive. Rather than treat nature and nurture as separable causal factors operating on development, they treat nature-nurture as a distinction between product (nature) versus process (nurture). Thus there has been a longstanding tension about how to define, separate, and balance the effects of nature and nurture.

• nature–nurture
• development
• nativism–empiricism
• innate–learned
• behavioral genetics
• epigenetics

Nature and Nurture in Development

The oldest and most persistent ways to frame explanations about the behavioral and mental development of individuals is to distinguish between two separate sources of developmental causation: (a) intrinsic, preformed, or predetermined causes (“nature”) versus (b) extrinsic, experiential, or environmental causes (“nurture”). Inputs from these two sources are thought to add their own contribution to development (see Figure 1 ).

Figure 1. The traditional view of nature and nurture as separate causes of development. In the traditional view, nature and nurture are treated as independent causal influences that combine during development to generate outcomes. Note that, during development, the effects of nature and nurture (shown in horizontal crossing lines) remain independent so that their effects on outcomes are theoretically separable.

Because some traits seem to derive more from one source than the other, much of the tension associated with the nature–nurture division deals with disagreements about how to balance the roles of nature and nurture in the development of a trait.

Evidence of Nature in Development

Evidence to support the nature–nurture division usually derives from patterns of behavior that suggest a limited role of environmental causation, thus implying some effect of nature by default. Table 1 depicts some common descriptors and conditions used to infer that some preference, knowledge, or skill is nature based.

Table 1. Common Descriptors and Associated Conditions for Inferring the Effects of Nature on Development

It is important to reiterate that nature-based causation (e.g., genetic determination) is inferred from these observations. Such inferences can generate tension because each of the observations listed here can be explained by nurture-based (environmental) factors. Confusion can also arise when evidence of one descriptor (e.g., being hereditary) is erroneously used to justify a different usage (e.g., that the trait is unlearned).

The Origins of Nature Versus Nurture

For much of recorded history, the distinction between nature and nurture was a temporal divide between what a person is innately endowed with at birth, prior to experience (nature), and what happens thereafter (nurture). It was not until the 19th century that the temporal division was transformed into a material division of causal influences (Keller, 2010 ). New views about heredity and Darwinian evolution justified distinguishing between native traits and genetic causes from acquired traits and environmental causes. More so than before, the terms nature and nurture were often juxtaposed in an opposition famously described by Sir Francis Galton ( 1869 ) as that between “nature versus nurture.”

Galton began writing about heredity in the mid-1860s. He believed we would discover laws governing the transmission of mental as well as physical qualities. Galton’s take on mental heredity, however, was forged by his desire to improve the human race in a science he would later call “eugenics.” In the mid- 19th century , British liberals assumed humans were equivalent at birth. Their social reform efforts were geared to enhancing educational opportunities and improving living conditions. Galton, a political conservative, opposed the notion of natural equality, arguing instead that people were inherently different at birth (Cowan, 2016 ), and that these inherited mental and behavioral inequalities were transmitted through lineages like physical qualities. Because Galton opposed the widely held Lamarckian idea that the qualities acquired in one’s lifetime could modify the inherited potential of subsequent generations, he believed long-lasting improvement of the human stock would only come by controlling breeding practices.

To explain the biological mechanisms of inheritance, Galton joined a growing trend in the 1870s to understand inheritance as involving the transmission of (hypothetical) determinative, germinal substances across generations. Foreshadowing a view that would later become scientific orthodoxy, Galton believed these germinal substances to be uninfluenced by the experiences of the organism. His theory of inheritance, however, was speculative. Realizing he was not equipped to fully explicate his theory of biological inheritance, Galton abandoned this line of inquiry by the end of that decade and refocused his efforts on identifying statistical laws of heredity of individual differences (Renwick, 2011 ).

Historians generally agree that Galton was the first to treat nature (as heredity) and nurture (everything else) as separate causal forces (Keller, 2010 ), but the schism gained biological legitimacy through the work of the German cytologist Auguste Weismann in the 1880s. Whereas Galton’s theory was motivated by his political agenda, Weismann was motivated by a scientific, theoretical agenda. Namely, Weismann opposed Lamarckian inheritance and promoted a view of evolution driven almost entirely by natural selection.

Drawing upon contemporary cytological and embryological research, Weismann made the case that the determinative substances found in the germ cells of plants and animals (called the “germ-plasm”) that are transmitted across generations were physically sequestered very early in embryogenesis and remained buffered from the other cells of the body (“somato-plasm”). This so-called, Weismann’s barrier meant that alterations in the soma that develop in the lifetime of the organism through the use or disuse of body parts would not affect the germinal substances transmitted during reproduction (see Winther, 2001 , for review). On this view, Lamarckian-style inheritance of acquired characteristics was not biologically possible.

Galton and Weismann’s influence on the life sciences cannot be overstated. Their work convinced many to draw unusually sharp distinctions between the inherited (nature) and the acquired (nurture). Although their theories were met with much resistance and generated significant tension in the life sciences from cytology to psychology, their efforts helped stage a new epistemic space through which to appreciate Mendel’s soon to be rediscovered breeding studies and usher in genetics (Muller-Wille & Rheinberger, 2012 ).

Ever since, psychology has teetered between nature-biased and nurture-biased positions. With the rise of genetics, the wedge between nature–nurture was deepened in the early to mid- 20th century , creating fields of study that focused exclusively on the effects of either nature or nurture.

The “Middle Ground” Perspective on Nature–Nurture

Twenty-first-century psychology textbooks often state that the nature–nurture debates have been resolved, and the tension relaxed, because we have moved on from emphasizing nature or nurture to appreciating that development necessarily involves both nature and nurture. In this middle-ground position, one asks how nature and nurture interact. For example, how do biological (or genetic) predispositions for behaviors or innate knowledge bias early learning experiences? Or how might environmental factors influence the biologically determined (maturational) unfolding of bodily form and behaviors?

Rejection of the Nature–Nurture Divide

For some, the “middle-ground” resolution is as problematic as “either/or” views and does not resolve a deeper source of tension inherent in the dichotomy. On this view, the nature–nurture divide is neither a legitimate nor a constructive way of thinking about development. Instead, developmental analysis reveals that the terms commonly associated with nature (e.g., innate, genetic, hereditary, or instinctual) and nurture (environmental or learned) are so entwined and confounded (and often arbitrary) that their independent effects cannot be meaningfully discussed. The nature–nurture division oversimplifies developmental processes, takes too much for granted, and ultimately hinders scientific progress. Thus not only is there a lingering tension about how to balance the effects of nature and nurture in the middle-ground view, but there is also a growing tension to move beyond the dichotomous nature–nurture framework.

Nativism in Behavior: Instincts

Definitions of instinct can vary tremendously, but many contrast (a) instinct with reason (or intellect, thought, will), which is related to but separable from contrasting (b) instinct with learning (or experience or habit).

Instinct in the Age of Enlightenment

Early usages of the instinct concept, following Aristotle, treated instinct as a mental, estimative faculty ( vis aestimativa or aestimativa naturalis ) in humans and animals that allowed for the judgments of objects in the world (e.g., seeing a predator) to be deemed beneficial or harmful in a way that transcends immediate sensory experience but does not involve the use of reason (Diamond, 1971 ). In many of the early usages, the “natural instinct” of animals even included subrational forms of learning.

The modern usage of instincts as unlearned behaviors took shape in the 17th century . By that point it was widely believed that nature or God had implanted in animals and humans innate behaviors and predispositions (“instincts”) to promote the survival of the individual and the propagation of the species. Disagreements arose as to whether instincts derived from innate mental images or were mindlessly and mechanically (physiologically) generated from innately specified bodily organization (Richards, 1987 ).

Anti-Instinct Movement in the Age of Enlightenment

Challenges to the instinct concept can be found in the 16th century (see Diamond, 1971 ), but they were most fully developed by empiricist philosophers of the French Sensationalist tradition in the 18th century (Richards, 1987 ). Sensationalists asserted that animals behaved rationally and all of the so-called instincts displayed by animals could be seen as intelligently acquired habits.

For Sensationalists, instincts, as traditionally understood, did not exist. Species-specificity in behavior patterns could be explained by commonalities in physiological organization, needs, and environmental conditions. Even those instinctual behaviors seen at birth (e.g., that newly hatched chicks peck and eat grain) might eventually be explained by the animal’s prenatal experiences. Erasmus Darwin ( 1731–1802 ), for example, speculated that the movements and swallowing experiences in ovo could account for the pecking and eating of grain by young chicks. The anti-instinct sentiment was clearly expressed by the Sensationalist Jean Antoine Guer ( 1713–1764 ), who warned that instinct was an “infantile idea” that could only be held by those who are ignorant of philosophy, that traditional appeals to instincts in animals not only explained nothing but served to hinder scientific explanations, and that nothing could be more superficial than to explain behavior than appealing to so-called instincts (Richards, 1987 ).

The traditional instinct concept survived. For most people, the complex, adaptive, species-specific behaviors displayed by naïve animals (e.g., caterpillars building cocoons; infant suckling behaviors) appeared to be predetermined and unlearned. Arguably as important, however, was the resistance to the theological implications of Sensationalist philosophy.

One of the strongest reactions to Sensationalism was put forward in Germany by Herman Samuel Reimarus ( 1694–1768 ). As a natural theologian, Reimarus, sought evidence of a God in the natural world, and the species-specific, complex, and adaptive instincts of animals seemed to stand as the best evidence of God’s work. More so than any other, Reimarus extensively catalogued instincts in humans and animals. Rather than treat instincts as behaviors, he defined instincts as natural impulses (inner drives) to act that were expressed perfectly, without reflection or practice, and served adaptive goals (Richards, 1987 ). He even proposed instincts for learning, a proposal that would resurface in the mid- 20th century , as would his drive theory of instinct (Jaynes & Woodward, 1974 ).

Partly as a result of Reimarus’ efforts, the instinct concept survived going into the 19th century . But many issues surrounding the instinct concept were left unsettled. How do instincts differ from reflexive behaviors? What role does learning play in the expression of instincts, if any? Do humans have more or fewer instincts than animals? These questions would persist well into the first decades of the 20th century and ultimately fuel another anti-instinct movement.

Instinct in the 19th Century

In the 19th century , the tension about the nature and nurture of instincts in the lifetime of animals led to debates about the nature and nurture of instincts across generations . These debates dealt with whether instincts should be viewed as “inherited habits” from previous generations or whether they result from the natural selection. Debating the relative roles of neo-Lamarckian use-inheritance versus neo-Darwinian natural selection in the transmutation of species became a significant source of tension in the latter half of the 19th century . Although the neo-Lamarckian notion of instincts as being inherited habits was rejected in the 20th century , it has resurged in recent years (e.g., see Robinson & Barron, 2017 ).

Darwinian evolutionary theory required drawing distinctions between native and acquired behaviors, and, perhaps more so than before, behaviors were categorized along a continuum from the purely instinctive (unlearned), to the partially instinctive (requiring some learning), to the purely learned. Still, it was widely assumed that a purely instinctive response would be modified by experience after its first occurrence. As a result, instinct and habit were very much entangled in the lifetime of the organism. The notion of instincts as fixed and unmodifiable would not be widely advanced until after the rise of Weismann’s germ-plasm theory in the late 19thcentury .

Given their importance in evolutionary theory, there was greater interest in more objectively identifying pure instincts beyond anecdotal reports. Some of the most compelling evidence was reported by Douglas Spalding ( 1844–1877 ) in the early 1870s (see Gray, 1967 ). Spalding documented numerous instances of how naïve animals showed coordinated, seemingly adaptive responses (e.g., hiding) to objects (e.g., sight of predators) upon their first encounter, and he helped pioneer the use of the deprivation experiment to identify instinctive behaviors. This technique involved selectively depriving young animals of seemingly critical learning experiences or sensory stimulation. Should animals display some species-typical action following deprivation, then, presumably, the behavior could be labeled as unlearned or innate. In all, these studies seemed to show that animals displayed numerous adaptive responses at the very start, prior to any relevant experience. In a variety of ways, Spalding’s work anticipated 20th-century studies of innate behavior. Not only would the deprivation experiment be used as the primary means of detecting native tendencies by European zoologists and ethologists, but Spalding also showed evidence of what would later be called imprinting, critical period effects and evidence of behavioral maturation.

Reports of pure instinct did not go unchallenged. Lloyd Morgan ( 1896 ) questioned the accuracy of these reports in his own experimental work with young animals. In some cases, he failed to replicate the results and in other cases he found that instinctive behaviors were not as finely tuned to objects in the environment as had been claimed. Morgan’s research pointed to taking greater precision in identifying learned and instinctive components of behavior, but, like most at the turn of the 20th century , he did not question that animal behavior involved both learned and instinctive elements.

A focus on instinctive behaviors intensified in the 1890s as Weismann’s germ-plasm theory grew in popularity. More so than before, a sharp distinction was drawn between native and acquired characteristics, including behavior (Johnston, 1995 ). Although some psychologists continued to maintain neo-Lamarckian notions, most German (Burnham, 1972 ) and American (Cravens & Burnham, 1971 ) psychologists were quick to adopt Weismann’s theory. They envisioned a new natural science of psychology that would experimentally identify the germinally determined, invariable set of native psychological traits in species and their underlying physiological (neural) basis. However, whereas English-speaking psychologists tended to focus on how this view impacted our understanding of social institutions and its social implications, German psychologists were more interested in the longstanding philosophical implications of Weismann’s doctrine as it related to the differences (if any) between man and beast (Burnham, 1972 ).

Some anthropologists and sociologists, however, interpreted Weismann’s theory quite differently and used it elevate sociology as its own scientific discipline. In the 1890s, the French sociologist Emil Durkheim, for example, interpreted Weismann’s germinal determinants as a generic force on human behavior that influenced the development of general predispositions that are molded by the circumstances of life (Meloni, 2016 ). American anthropologists reached similar conclusions in the early 20th century (Cravens & Burnham, 1971 ). Because Weismann’s theory divorced biological inheritance from social inheritance, and because heredity was treated as a generic force, sociologists felt free to study social (eventually, “cultural”) phenomena without reference to biological or psychological concerns.

Anti-Instinct Movement in the 1920s

Despite their differences, in the first two decades of the 20th century both psychologists and sociologists generally assumed that humans and animals had some native tendencies or instincts. Concerns were even voiced that instinct had not received enough attention in psychology. Disagreements about instincts continued to focus on (the now centuries old debates of) how to conceptualize them. Were they complex reflexes, impulses, or motives to act, or should instinct be a mental faculty (like intuition), separate from reasoning and reflex (Herrnstein, 1972 )?

In America, the instinct concept came under fire following a brief paper in 1919 by Knight Dunlap titled “Are There Any Instincts?” His primary concern dealt with teleological definitions of instincts in which an instinct referred to all the activities involved in obtaining some end-state (e.g., instincts of crying, playing, feeding, reproduction, war, curiosity, or pugnacity). Defined in this way, human instincts were simply labels for human activities, but how these activities were defined was arbitrarily imposed by the researchers. Is feeding, for instance, an instinct, or is it composed of more basic instincts (like chewing and swallowing)? The arbitrariness of classifying human behavior had led to tremendous inconsistencies and confusion among psychologists.

Not all of the challenges to instinct dealt with its teleological usage. Some of the strongest criticisms were voiced by Zing-Yang Kuo throughout the 1920s. Kuo was a Chinese animal psychologist who studied under Charles Tolman at the University of California, Berkeley. Although Kuo’s attacks on instinct changed throughout the 1920s (see Honeycutt, 2011 ), he ultimately argued that all behaviors develop in experience-dependent ways and that appeals to instinct were statements of ignorance about how behaviors develop. Like Dunlap, he warned that instincts were labels with no explanatory value. To illustrate, after returning to China, he showed how the so-called rodent-killing instinct in cats often cited by instinct theorists is not found in kittens that are reared with rodents (Kuo, 1930 ). These kittens, instead, became attached to the rodents, and they resisted attempts to train rodent-killing. Echoing the point made by Guer, Kuo claimed that appeals to instinct served to stunt scientific inquiry into the developmental origins of behavior.

But Kuo did not just challenge the instinct concept. He also argued against labeling behaviors as “learned.” After all, whether an animal “learns” depends on the surrounding environmental conditions, the physiological and developmental status of the animal, and, especially, the developmental (or experiential) history of that animal. Understanding learning also required developmental analysis. Thus Kuo targeted the basic distinction between nature and nurture, and he was not alone in doing so (e.g., see Carmichael, 1925 ), but his call to reject it did not spread to mainstream American psychologists.

By the 1930s, the term instinct had fallen into disrepute in psychology, but experimental psychologists (including behaviorists) remained committed to a separation of native from acquired traits. If anything, the dividing line between native and acquired behaviors became more sharply drawn than before (Logan & Johnston, 2007 ). For some psychologists, instinct was simply rebranded in the less contentious (but still problematic) language of biological drives or motives (Herrnstein, 1972 ). Many other psychologists simply turned to describing native traits as due to “maturation” and/or “heredity” rather than “instinct.”

Fixed Action Patterns

The hereditarian instinct concept received a reboot in Europe in the 1930s with the rise of ethology led by Konrad Lorenz, Niko Tinbergen, and others. Just as animals inherit organs that perform specific functions, ethologists believed animals inherit behaviors that evolved to serve adaptive functions as well. Instincts were described as unlearned (inherited), blind, stereotyped, adaptive, fixed action patterns, impervious to change that are initiated (released) by specific stimuli in the environment.

Ethologists in 1930s and 1940s were united under the banner of innateness. They were increasingly critical of the trend by American psychologists (i.e., behaviorists) to focus on studying on how a limited number of domesticated species (e.g., white rat) responded to training in artificial settings (Burkhardt, 2005 ). Ethologists instead began with rich descriptions of animal behavior in more natural environments along with detailed analyses of the stimulus conditions that released the fixed action patterns. To test whether behavioral components were innate, ethologists relied primarily on the deprivation experiment popularized by Spalding in the 19th century . Using these methods (and others), ethologists identified numerous fascinating examples of instinctive behaviors, which captured mainstream attention.

In the early 1950s, shortly after ethology had gained professional status (Burkhardt, 2005 ), a series of challenges regarding instinct and innateness were put forth by a small cadre of North American behavioral scientists (e.g., T. C. Schneirla, Donald Hebb, Frank Beach). Arguably the most influential critique was voiced by comparative psychologist Daniel Lehrman ( 1953 ), who presented a detailed and damning critique of deprivation experiments on empirical and logical grounds. Lehrman explained that deprivation experiments isolate the animal from some but not all experiences. Thus deprivation experiments simply change what an animal experiences rather than eliminating experience altogether, and so they cannot possibly determine whether a behavior is innate (independent of experience). Instead, these experiments show what environmental conditions do not matter in the development of a behavior but do not speak to what conditions do matter .

Lehrman went on to argue that the whole endeavor to identify instinctive or innate behavior was misguided from the start. All behavior, according to Lehrman, develops from a history of interactions between an organism and its environment. If a behavior is found to develop in the absence of certain experiences, the researcher should not stop and label it as innate. Rather, research should continue to identify the conditions under which the behavior comes about. In line with Kuo, Lehrman repeated the warning that to label something as instinctive (or inherited or maturational) is a statement of ignorance about how that behavior develops and does more to stunt than promote research.

Lehrman’s critique created significant turmoil among ethologists. As a result, ethologists took greater care in using the term innate , and it led to new attempts to synthesize or re-envision learning and instinct .

Some of these attempts focused on an increased role for learning and experience in the ontogeny of species-typical behaviors. These efforts spawned significant cross-talk between ethologists and comparative psychologists to more thoroughly investigate behavioral development under natural conditions. Traditional appeals to instinct and learning (as classical and operant conditioning) were both found to be inadequate for explaining animal behavior. In their stead, these researchers focused more closely on how anatomical, physiological, experiential, and environmental conditions influenced the development of species-typical behaviors.

Tinbergen ( 1963 ) was among those ethologists who urged for greater developmental analysis of species-typical behaviors, and he included it as one of his four problems in the biological study of organisms, along with causation (mechanism), survival value (function), and evolution. Of these four problems, Tinbergen believed ethologists were especially well suited to study survival value, which he felt had been seriously neglected (Burkhardt, 2005 ).

The questions of survival value coupled with models of population genetics would gain significant momentum in the 1960s and 1970s in England and the United States with the rise of behavioral ecology and sociobiology (Griffiths, 2008 ). But because these new fields seemed to promote some kind of genetic determinism in behavioral development, they were met with much resistance and reignited a new round of nature–nurture debates in the 1970s (see Segerstrale, 2000 ).

However, not all ethologists abandoned the instinct concept. Lorenz, in particular, continued to defend the division between nature and nurture. Rather than speaking of native and acquired behaviors, Lorenz later spoke of two different sources of information for behavior (innate/genetic vs. acquired/environmental), which was more a subtle shift in language than it was an actual change in theory, as Lehrman later pointed out.

Some ethologists followed Lorenz’s lead and continued to maintain more of a traditional delineation between instinct and learning. Their alternative synthesis viewed learning as instinctive (Gould & Marler, 1987 ). They proposed that animals have evolved domain-specific “instincts to learn” that result from the its genetic predispositions and innate knowledge. To support the idea of instincts for learning, ethologists pointed to traditional ethological findings (on imprinting and birdsong learning), but they also drew from the growing body of work in experimental psychology that seemed to indicate certain types of biological effects on learning.

Biological Constraints and Preparedness

While ethology was spreading in Europe in the 1930s–1950s, behaviorism reigned in the United States. Just as ethologists were confronted with including a greater role of nurture in their studies, behaviorists were challenged to consider a greater role of nature.

Behaviorists assumed there to be some behavioral innateness (e.g., fixed action patterns, unconditioned reflexes, primary reinforcers and drives). But because behaviorists focused on learning, they tended to study animals in laboratory settings using biologically (or ecologically) irrelevant stimuli and responses to minimize any role of instinct (Johnston, 1981 ). It was widely assumed that these studies would identify general laws of learning that applied to all species regardless of the specific cues, reinforcers, and responses involved.

Challenges to the generality assumption began to accumulate in the 1960s. Some studies pointed to failures that occurred during conditioning procedures. Breland and Breland ( 1961 ), for example, reported that some complex behaviors formed through operant conditioning would eventually become “displaced” by conditioned fixed action patterns in a phenomenon they called “instinctive drift.” Studies of taste-aversion learning (e.g., Garcia & Koelling, 1966 ) also reported the failure of rats to associate certain events (e.g., flavors with shock or audiovisual stimuli with toxicosis).

Other studies were pointing to enhanced learning. In particular, it was found that rats could form strong conditioned taste aversions after only a single pairing between a novel flavor and illness. (This rapid “one trial learning” was a major focus in the research from Niko Tinbergen’s ethological laboratory.) Animals, it seemed, had evolved innate predispositions to form (or not form) certain associations.

In humans, studies of biological constraints on learning were mostly limited to fear conditioning. Evidence indicated that humans conditioned differently to (biologically or evolutionarily) fear-relevant stimuli like pictures of spiders or snakes than to fear-irrelevant stimuli like pictures of mushrooms or flowers (Ohman, Fredrikson, Hugdahl, & Rimmö, 1976 ).

These findings and others were treated as a major problem in learning theory and led to calls for a new framework to study learning from a more biologically oriented perspective that integrated the evolutionary history and innate predispositions of the species. These predispositions were described as biological “constraints” on, “preparedness,” or “adaptive specializations” for learning, all of which were consistent with the “instincts to learn” framework proposed by ethologists.

By the 1980s it was becoming clear that the biological preparedness/constraint view of learning suffered some limitations. For example, what constraints count as “biological” was questioned. It was well established that there were general constraints on learning associated with the intensity, novelty, and timing of stimuli. But, arbitrarily it seemed, these constraints were not classified as “biological” (Domjan & Galef, 1983 ). Other studies of “biological constraints” found that 5- and 10-day old rats readily learned to associated a flavor with shock (unlike in adults), but (like in adults) such conditioning was not found in 15-day-old rats (Hoffman & Spear, 1988 ). In other words, the constraint on learning was not present in young rats but developed later in life, suggesting a possible role of experience in bringing about the adult-like pattern.

Attempts to synthesize these alternatives led to numerous calls for more ecologically oriented approaches to learning not unlike the synthesis between ethology and comparative psychology in the 1960s. All ecological approaches to learning proposed that learning should be studied in the context of “natural” (recurrent and species-typical) problems that animals encounter (and have evolved to encounter) using ecologically meaningful stimuli and responses. Some argued (e.g., Johnston, 1981 ) that studies of learning should take place within the larger context of studying how animals develop and adapt to their surround. Others (Domjan & Galef, 1983 ) pointed to more of a comparative approach in studying animal learning in line with behavioral ecology that takes into account how learning can be influenced by the possible selective pressures faced by each species. Still, how to synthesize biological constraints (and evolutionary explanations) on learning with a general process approach remains a source of tension in experimental psychology.

Nativism in Mind: Innate Ideas

Nativism and empiricism in philosophy.

In the philosophy of mind, nature–nurture debates are voiced as debates between nativists and empiricists. Nativism is a philosophical position that holds that our minds have some innate (a priori to experience) knowledge, concepts, or structure at the very start of life. Empiricism, in contrast, holds that all knowledge derives from our experiences in the world.

However, rarely (if ever) were there pure nativist or empiricist positions, but the positions bespeak a persistent tension. Empiricists tended to eschew innateness and promote a view of the mental content that is built by general mechanisms (e.g., association) operating on sensory experiences, whereas nativists tend to promote a view of mind that contains domain-specific, innate processes and/or content (Simpson, Carruthers, Laurence, & Stich, 2005 ). Although the tension about mental innateness would loosen as empiricism gained prominence in philosophy and science, the strain never went away and would intensify again in the 20th century .

Nativism in 20th Century Psychology: The Case of Language Development

In the first half of the 20th century , psychologists generally assumed that knowledge was gained or constructed through experience with the world. This is not to say that psychologists did not assume some innate knowledge. The Swiss psychologist Jean Piaget, for example, believed infants enter the world with some innate knowledge structures, particularly as they relate to early sensory and motor functioning (see Piaget, 1971 ). But the bulk of his work dealt with the construction of conceptual knowledge as children adapt to their worlds. By and large, there were no research programs in psychology that sought to identify innate factors in human knowledge and cognition until the 1950s (Samet & Zaitchick, 2017 )

An interest in psychological nativism was instigated in large part by Noam Chomsky’s ( 1959 ) critique of B. F. Skinner’s book on language. To explain the complexity of language, he argued, we must view language as the knowledge and application of grammatical rules. He went on to claim that the acquisition of these rules could not be attributed to any general-purpose, learning process (e.g., reinforcement). Indeed, language acquisition occurs despite very little explicit instruction. Moreover, language is special in terms of its complexity, ease, and speed of acquisition by children and in its uniqueness to humans. Instead, he claimed that our minds innately contain some language-specific knowledge that kick-starts and promotes language acquisition. He later claimed this knowledge can be considered some sort of specialized mental faculty or module he called the “language acquisition device” (Chomsky, 1965 ) or what Pinker ( 1995 ) later called the “language instinct.”

To support the idea of linguistic nativism, Chomsky and others appealed to the poverty of the stimulus argument. In short, this argument holds that our experiences in life are insufficient to explain our knowledge and abilities. When applied to language acquisition, this argument holds children’s knowledge of language (grammar) goes far beyond the limited, and sometimes broken, linguistic events that children directly encounter. Additional evidence for nativism drew upon the apparent maturational quality of language development. Despite wide variations in languages and child-rearing practices across the world, the major milestones in language development appear to unfold in children in a universal sequence and timeline, and some evidence suggested a critical period for language acquisition.

Nativist claims about language sparked intense rebuttals by empiricist-minded psychologists and philosophers. Some of these retorts tackled the logical limitations of the poverty of stimulus argument. Others pointed to the importance of learning and social interaction in driving language development, and still others showed that language (grammatical knowledge) may not be uniquely human (see Tomasello, 1995 , for review). Nativists, in due course, provided their own rebuttals to these challenges, creating a persistent tension in psychology.

Extending Nativism Beyond Language Development

In the decades that followed, nativist arguments expanded beyond language to include cognitive domains that dealt with understanding the physical, psychological, and social worlds. Developmental psychologists were finding that infants appeared to be much more knowledgeable in cognitive tasks (e.g., on understanding object permanence) and skillful (e.g., in imitating others) than had previously been thought, and at much younger ages. Infants also showed a variety of perceptual biases (e.g., preference for face-like stimuli over equally complex non-face-like stimuli) from very early on. Following the standard poverty of the stimulus argument, these findings were taken as evidence that infants enter the world with some sort of primitive, innate, representational knowledge (or domain-specific neural mechanisms) that constrains and promotes subsequent cognitive development. The nature of this knowledge (e.g., as theories or as core knowledge), however, continues to be debated (Spelke & Kinzler, 2007 ).

Empiricist-minded developmental psychologists responded by demonstrating shortcomings in the research used to support nativist claims. For example, in studies of infants’ object knowledge, the behavior of infants (looking time) in nativist studies could be attributed to relatively simple perceptual processes rather than to the infants’ conceptual knowledge (Heyes, 2014 ). Likewise, reports of human neonatal imitation not only suffered from failures to replicate but could be explained by simpler mechanisms (e.g., arousal) than true imitation (Jones, 2017 ). Finally, studies of perceptual preferences found in young infants, like newborn preferences for face-like stimuli, may not be specific preferences for faces per se but instead may reflect simpler, nonspecific perceptual biases (e.g., preferences for top-heavy visual configurations and congruency; Simion & Di Giorgio, 2015 ).

Other arguments from empiricist-minded developmental psychologists focused on the larger rationale for inferring innateness. Even if it is conceded that young infants, like two-month-olds, or even two-day-olds, display signs of conceptual knowledge, there is no good evidence to presume the knowledge is innate. Their knowledgeable behaviors could still be seen as resulting from their experiences (many of which may be nonobvious to researchers) leading up to the age of testing (Spencer et al., 2009 ).

In the 21st century , there is still no consensus about the reality, extensiveness, or quality of mental innateness. If there is innate knowledge, can experience add new knowledge or only expand the initial knowledge? Can the doctrine of innate knowledge be falsified? There are no agreed-upon answers to these questions. The recurring arguments for and against mental nativism continue to confound developmental psychologists.

Maturation Theory

The emergence of bodily changes and basic behavioral skills sometimes occurs in an invariant, predictable, and orderly sequence in a species despite wide variations in rearing conditions. These observations are often attributed to the operation of an inferred, internally driven, maturational process. Indeed, 21st-century textbooks in psychology commonly associate “nature” with “maturation,” where maturation is defined as the predetermined unfolding of the individual from a biological or genetic blueprint. Environmental factors play a necessary, but fundamentally supportive, role in the unfolding of form.

Preformationism Versus Epigenesis in the Generation of Form

The embryological generation of bodily form was debated in antiquity but received renewed interest in the 17th century . Following Aristotle, some claimed that embryological development involved “epigenesis,” defined as the successive emergence of form from a formless state. Epigenesists, however, struggled to explain what orchestrated development without appealing to Aristotelean souls. Attempts were made to invoke to natural causes like physical and chemical forces, but, despite their best efforts, the epigenesists were forced to appeal to the power of presumed, quasi-mystical, vitalistic forces (entelechies) that directed development.

The primary alternative to epigenesis was “preformationism,” which held that development involved the growth of pre-existing form from a tiny miniature (homunculus) that formed immediately after conception or was preformed in the egg or sperm. Although it seems reasonable to guess that the invention and widespread use of the microscope would immediately lay to rest any claim of homuncular preformationism, this was not the case. To the contrary, some early microscopists claimed to see signs of miniature organisms in sperm or eggs, and failures to find these miniatures were explained away (e.g., the homunculus was transparent or deflated to the point of being unrecognizable). But as microscopes improved and more detailed observations of embryological development were reported in the late 18th and 19th centuries , homuncular preformationism was finally refuted.

From Preformationism to Predeterminism

Despite the rejection of homuncular preformationism, preformationist appeals can be found throughout the 19th century . One of the most popular preformationist theories of embryological development was put forth by Ernst Haeckel in the 1860s (Gottlieb, 1992 ). He promoted a recapitulation theory (not original to Haeckel) that maintained that the development of the individual embryo passes through all the ancestral forms of its species. Ontogeny was thought to be a rapid, condensed replay of phylogeny. Indeed, for Haeckel, phylogenesis was the mechanical cause of ontogenesis. The phylogenetic evolution of the species created the maturational unfolding of embryonic form. Exactly how this unfolding takes place was less important than its phylogenetic basis.

Most embryologists were not impressed with recapitulation theory. After all, the great embryologist Karl Ernst von Baer ( 1792–1876 ) had refuted strict recapitulation decades earlier. Instead, there was greater interest in how best to explain the mechanical causes of development ushering in a new “experimental embryology.” Many experimental embryologists followed the earlier epigenesists by discussing vitalistic forces operating on the unorganized zygote. But it soon became clear that the zygote was structured, and many people believed the zygote contained special (unknown) substances that specified development. Epigenesis-minded experimental embryologists soon warned that the old homuncular preformationism was being transformed into a new predetermined preformationism.

As a result, the debates between preformationism and epigenesis were reignited in experimental embryology, but the focus of these debates shifted to the various roles of nature and nurture during development. More specifically, research focused on the extent to which early cellular differentiation was predetermined by factors internal to cells like chromosomes or cytoplasm (preformationism, nature) or involved factors (e.g., location) outside of the cell (epigenesis, nurture). The former emphasized reductionism and developmental programming, whereas the latter emphasized some sort of holistic, regulatory system responsive to internal and external conditions. The tension between viewing development as predetermined or “epigenetic” persists into the 21st century .

Preformationism gained momentum in the 20th century following the rediscovery of Mendel’s studies of heredity and the rapid rise of genetics, but not because of embryological research on the causes of early differentiation. Instead, preformationism prevailed because it seemed embryological research on the mechanisms of development could be ignored in studies of hereditary patterns.

The initial split between heredity and development can be found in Galton’s speculations but is usually attributed to Weismann’s germ-plasm theory. Weismann’s barrier seemed to posit that the germinal determinants present at conception would be the same, unaltered determinants transmitted during reproduction. This position, later dubbed as “Weismannism,” was ironically not one promoted by Weismann. Like nearly all theorists in the 19th century , he viewed the origins of variation and heredity as developmental phenomena (Amundson, 2005 ), and he claimed that the germ-plasm could be directly modified in the lifetime of the organism by environmental (e.g., climactic and dietary) conditions (Winther, 2001 ). Still, Weismann’s theory treated development as a largely predetermined affair driven by inherited, germinal determinants buffered from most developmental events. As such, it helped set the stage for a more formal divorce between heredity and development with the rise of Mendelism in the early 20th century .

Mendel’s theory of heredity was exceptional in how it split development from heredity (Amundson, 2005 ). More so than in Weismann’s theory, Mendel’s theory assumed that the internal factors that determine form and are transmitted across generations remain unaltered in the lifetime of the organism. To predict offspring outcomes, one need only know the combination of internal factors present at conception and their dominance relations. Exactly how these internal factors determined form could be disregarded. The laws of hereditary transmission of the internal factors (e.g., segregation) did not depend on the development or experiences of the organism or the experiences the organism’s ancestors. Thus the experimental study of heredity (i.e., breeding) could proceed without reference to ancestral records or embryological concerns (Amundson, 2000 ). By the mid-1920s, the Mendelian factors (now commonly called “genes”) were found to be structurally arranged on chromosomes, and the empirical study of heredity (transmission genetics) was officially divorced from studies of development.

The splitting of heredity and development found in Mendel’s and Weismann’s work met with much resistance. Neo-Lamarckian scientists, especially in the United States (Cook, 1999 ) and France (Loison, 2011 ), sought unsuccessfully to experimentally demonstrate the inheritance of acquired characteristics into the 1930s.

In Germany during the 1920s and 1930s, resistance to Mendelism dealt with the chromosomal view of Mendelian heredity championed by American geneticists who were narrowly focused on studying transmission genetics at the expense of developmental genetics. German biologists, in contrast, were much more interested in the broader roles of genes in development (and evolution). In trying to understand how genes influence development, particularly of traits of interest to embryologists, they found the Mendelian theory to be lacking. In the decades between the world wars, German biologists proposed various expanded views of heredity that included some form of cytoplasmic inheritance (Harwood, 1985 ).

Embryologists resisted the preformationist view of development throughout the early to mid- 20th century , often maintaining no divide between heredity and development, but their objections were overshadowed by genetics and its eventual synthesis with evolutionary theory. Consequently, embryological development was treated by geneticists and evolutionary biologists as a predetermined, maturational process driven by internal, “genetic” factors buffered from environmental influence.

Maturation Theory in Psychology

Maturation theory was applied to behavioral development in the 19th century in the application of Haeckel’s recapitulation theory. Some psychologists believed that the mental growth of children recapitulated the history of the human race (from savage brute to civilized human). With this in mind, many people began to more carefully document child development. Recapitulationist notions were found in the ideas of many notable psychologists in the 19th and early 20th centuries (e.g., G. S. Hall), and, as such, the concept played an important role in the origins of developmental psychology (Koops, 2015 ). But for present purposes what is most important is that children’s mental and behavioral development was thought to unfold via a predetermined, maturational process.

With the growth of genetics, maturational explanations were increasingly invoked to explain nearly all native and hereditary traits. As the instinct concept lost value in the 1920s, maturation theory gained currency, although the shift was largely a matter of semantics. For many psychologists, the language simply shifted from “instinct versus learning” to “maturation versus practice/experience” (Witty & Lehman, 1933 ).

Initial lines of evidence for maturational explanations of behavior were often the same as those that justified instinct and native traits, but new embryological research presented in the mid-1920s converged to show support for strict maturational explanations of behavioral development. In these experiments (see Wyman, 2005 , for review), spanning multiple laboratories, amphibians (salamanders and frogs) were exposed to drugs that acted as anesthetics and/or paralytics throughout the early stages of development, thus reducing sensory experience and/or motor practice. Despite the reduced sensory experiences and being unable to move, these animals showed no delays in the onset of motor development once the drugs wore off.

This maturational account of motor development in amphibians fit well with contemporaneous studies of motor development in humans. The orderly, invariant, and predictable (age-related) sequential appearance of motor skills documented in infants reared under different circumstances (in different countries and across different decades) was seen as strong evidence for a maturational account. Additional evidence was reported by Arnold Gessell and Myrtle McGraw, who independently presented evidence in the 1920s to show that the pace and sequence of motor development in infancy were not altered by special training experiences. Although the theories of these maturation theorists were more sophisticated when applied to cognitive development, their work promoted a view in which development was primarily driven by neural maturation rather than experience (Thelen, 2000 ).

Critical and Sensitive Periods

As the maturation account of behavioral development gained ground, it became clear that environmental input played a more informative role than had previously been thought. Environmental factors were found to either disrupt or induce maturational changes at specific times during development. Embryological research suggested that there were well-delineated time periods of heightened sensitivity in which specific experimental manipulations (e.g., tissue transplantations) could induce irreversible developmental changes, but the same manipulation would have no effect outside of that critical period.

In the 1950s–1960s a flurry of critical period effects were reported in birds and mammals across a range of behaviors including imprinting, attachment, socialization, sensory development, bird song learning, and language development (Michel & Tyler, 2005 ). Even though these findings highlighted an important role of experience in behavioral development, evidence of critical periods was usually taken to imply some rigid form of biological determinism (Oyama, 1979 ).

As additional studies were conducted on critical period effects, it became clear that many of the reported effects were more gradual, variable, experience-dependent, and not necessarily as reversible as was previously assumed. In light of these reports, there was a push in the 1970s (e.g., Connolly, 1972 ) to substitute “sensitive period” for “critical period” to avoid the predeterminist connotations associated with the latter and to better appreciate that these periods simply describe (not explain) certain temporal aspects of behavioral development. As a result, a consensus emerged that behaviors should not be attributed to “time” or “age” but to the developmental history and status of the animal under investigation (Michel & Tyler, 2005 ).

Heredity and Genetics

In the decades leading up to and following the start of the 20th century , it was widely assumed that many psychological traits (not just instincts) were inherited or “due to heredity,” although the underlying mechanisms were unknown. Differences in intelligence, personality, and criminality within and between races and sexes were largely assumed to be hereditary and unalterable by environmental intervention (Gould, 1996 ). The evidence to support these views in humans was often derived from statistical analyses of how various traits tended to run in families. But all too frequently, explanations of data were clouded by pre-existing, hereditarian assumptions.

Human Behavioral Genetics

The statistical study of inherited human (physical, mental, and behavioral) differences was pioneered by Galton ( 1869 ). Although at times Galton wrote that nature and nurture were so intertwined as to be inseparable, he nevertheless devised statistical methods to separate their effects. In the 1860s and 1870s, Galton published reports purporting to show how similarities in intellect (genius, talent, character, and eminence) in European lineages appeared to be a function of degree of relatedness. Galton considered, but dismissed, environmental explanations of his data, leading him to confirm his belief that nature was stronger than nurture.

Galton also introduced the use of twin studies to tease apart the relative impact of nature versus nurture, but the twin method he used was markedly different from later twin studies used by behavioral geneticists. Galton tracked the life history of twins who were judged to be very similar or very dissimilar near birth (i.e., by nature) to test the power of various postnatal environments (nurture) that might make them more or less similar over time. Here again, Galton concluded that nature overpowers nurture.

Similar pedigree (e.g., the Kallikak study; see Zenderland, 2001 ) and twin studies appeared in the early 1900s, but the first adoption study and the modern twin method (which compares monozygotic to dizygotic twin pairs) did not appear until the 1920s (Rende, Plomin, & Vandenberg, 1990 ). These reports led to a flurry of additional work on the inheritance of mental and behavioral traits over the next decade.

Behavioral genetic research peaked in the 1930s but rapidly lost prominence due in large part to its association with the eugenics movement (spearheaded by Galton) but also because of the rise and eventual hegemony of behaviorism and the social sciences in the United States. Behavioral genetics resurged in the 1960s with the rising tide of nativism in psychology, and returned to its 1930s-level prominence in the 1970s (McGue & Gottesman, 2015 ).

The resurgence brought with a new statistical tool: the heritability statistic. The origins of heritability trace back to early attempts to synthesize Mendelian genetics with biometrics by Ronald Fisher and others. This synthesis ushered in a new field of quantitative genetics and it marked a new way of thinking about nature and nurture. The shift was to no longer think about nature and nurture as causes of traits in individuals but as causes of variation in traits between populations of individuals. Eventually, heritability came to refer to the amount of variance in a population sample that could be statistically attributed to genetic variation in that sample. Kinship (especially twin) studies provided seemingly straightforward ways of partitioning variation in population trait attributes into genetic versus environmental sources.

Into the early 21st century , hundreds of behavioral genetic studies of personality, intelligence, and psychopathology were reported. With rare exceptions, these studies converge to argue for a pervasive influence of genetics on human psychological variation.

These studies have also fueled much controversy. Citing in part behavioral genetic research, the educational psychologist Arthur Jensen ( 1969 ) claimed that the differences in intelligence and educational achievement in the United States between black and white students appeared to have a strong genetic basis. He went on to assume that because these racial differences appeared hereditary, they were likely impervious to environmental (educational) intervention. His article fanned the embers of past eugenics practices and ignited fiery responses (e.g., Hirsch, 1975 ). The ensuing debates not only spawned a rethinking of intelligence and how to measure it, but they ushered in a more critical look at the methods and assumptions of behavioral genetics.

Challenges to Behavioral Genetics

Many of the early critiques of behavioral genetics centered on interpreting the heritability statistic commonly calculated in kinship (family, twin, and adoption) studies. Perhaps more so than any other statistic, heritability has been persistently misinterpreted by academics and laypersons alike (Lerner, 2002 ). Contrary to popular belief, heritability tells us nothing about the relative impact of genetic and environmental factors on the development of traits in individuals. It deals with accounting for trait variation between people, not the causes of traits within people. As a result, a high heritability does not indicate anything about the fixity of traits or their imperviousness to environmental influence (contra Jensen), and a low heritability does not indicate an absence of genetic influence on trait development. Worse still, heritability does not even indicate anything about the role of genetics in generating the differences between people.

Other challenges to heritability focused not on its interpretation but on its underlying computational assumptions. Most notably, heritability analyses assume that genetic and environmental contributions to trait differences are independent and additive. The interaction between genetic and environmental factors were dismissed a priori in these analyses. Studies of development, however, show that no factor (genes, hormones, parenting, schooling) operates independently, making it impossible to quantify how much of a given trait in a person is due to any causal factor. Thus heritability analyses are bound to be misleading because they are based on biologically implausible and logically indefensible assumptions about development (Gottlieb, 2003 ).

Aside from heritability, kinship studies have been criticized for not being able to disentangle genetic and environmental effects on variation. It had long been known that that in family (pedigree) studies, environmental and genetic factors are confounded. Twin and adoption studies seemed to provide unique opportunities to statistically disentangle these effects, but these studies are also deeply problematic in assumptions and methodology. There are numerous plausible environmental reasons for why monozygotic twin pairs could resemble each other more than dizygotic twin pairs or why adoptive children might more closely resemble their biological than their adoptive parents (Joseph & Ratner, 2013 ).

A more recent challenge to behavioral genetics came from an unlikely source. Advances in genomic scanning in the 21st century made it possible in a single study to correlate thousands of genetic polymorphisms with variation in the psychological profiles (e.g., intelligence, memory, temperament, psychopathology) of thousands of people. These “genome-wide association” studies seemed to have the power and precision to finally identify genetic contributions to heritability at the level of single nucleotides. Yet, these studies consistently found only very small effects.

The failure to find large effects came to be known as the “missing heritability” problem (Maher, 2008 ). To account for the missing heritability, some behavioral geneticists and molecular biologists asserted that important genetic polymorphisms remain unknown, they may be too rare to detect, and/or that current studies are just not well equipped to handle gene–gene interactions. These studies were also insensitive to epigenetic profiles (see the section on Behavioral Epigenetics), which deal with differences in gene expression. Even when people share genes, they may differ in whether those genes get expressed in their lifetimes.

But genome-wide association studies faced an even more problematic issue: Many of these studies failed to replicate (Lickliter & Honeycutt, 2015 ). For those who viewed heritability analyses as biologically implausible, the small effect sizes and failures to replicate in genome-wide association studies were not that surprising. The search for independent genetic effects was bound to fail, because genes simply do not operate independently during development.

Behavioral Epigenetics

Epigenetics was a term coined in the 1940s by the developmental biologist Conrad Waddington to refer to a new field of study that would examine how genetic factors interact with local environmental conditions to bring about the embryological development of traits. By the end of the 20th century , epigenetics came to refer to the study of how nongenetic, molecular mechanisms physically regulate gene expression patterns in cells and across cell lineages. The most-studied mechanisms involve organic compounds (e.g., methyl-groups) that physically bind to DNA or the surrounding proteins that package DNA. The addition or removal of these compounds can activate or silence gene transcription. Different cell types have different, stable epigenetic markings, and these markings are recreated during cell division so that cells so marked give rise to similar types of cells. Epigenetic changes were known to occur during developmental periods of cellular differentiation (e.g., during embryogenesis), but not until 2004 was it discovered that these changes can occur at other periods in the life, including after birth (Roth, 2013 )

Of interest to psychologists were reports that different behavioral and physiological profiles (e.g., stress reactivity) of animals were associated with different epigenetic patterns in the nervous system (Moore, 2015 ). Furthermore, these different epigenetic patterns could be established or modified by environmental factors (e.g., caregiving practices, training regimes, or environmental enrichment), and, under certain conditions, they remain stable over long periods of time (from infancy to adulthood).

Because epigenetic research investigates the physical interface between genes and environment, it represents an exciting advance in understanding the interaction of nature and nurture. Despite some warnings that the excitement over behavioral epigenetic research may be premature (e.g., Miller, 2010 ), for many psychologists, epigenetics underscores how development involves both nature and nurture.

For others, what is equally exciting is the additional evidence epigenetics provides to show that the genome is an interactive and regulated system. Once viewed as the static director of development buffered from environment influence, the genome is better described as a developing resource of the cell (Moore, 2015 ). More broadly, epigenetics also points to how development is not a genetically (or biologically) predetermined affair. Instead, epigenetics provides additional evidence that development is a probabilistic process, contingent upon factors internal and external to the organism. In this sense, epigenetics is well positioned to help dissolve the nature–nurture dichotomy.

Beyond Nature–Nurture

In the final decades of the 20th century , a position was articulated to move beyond the dichotomous nature–nurture framework. The middle-ground position on nature–nurture did not seem up to the task of explaining the origins of form, and it brought about more confusion than clarity. The back-and-forth (or balanced) pendulum between nature- and nurture-based positions throughout history had only gone in circles. Moving forward would require moving beyond such dichotomous thinking (Johnston, 1987 ).

The anti-dichotomy position, referred to as the Developmentalist tradition, was expressed in a variety of systems-based, metatheoretical approaches to studying development, all of which extended the arguments against nature–nurture expressed earlier by Kuo and Lehrman. The central problem with all nativist claims according to Developmentalists is a reliance on preformationism (or predeterminism).

The problem with preformationism, they argue, besides issues of evidence, is that it is an anti-developmental mindset. It presumes the existence of the very thing(s) one wishes to explain and, consequently, discourages developmental analyses. To claim that some knowledge is innate effectively shuts down research on the developmental origins of that knowledge. After all, why look for the origins of conceptual knowledge if that knowledge is there all along? Or why search for any experiential contributions to innate behaviors if those behaviors by definition develop independently of experience? In the words of Developmentalists Thelen and Adolph ( 1992 ), nativism “leads to a static science, with no principles for understanding change or for confronting the ultimate challenge of development, the source of new forms in structure and function” (p. 378).

A commitment to maturational theory is likely one of the reasons why studies of motor development remained relatively dormant for decades following its heyday in the 1930–1940s (Thelen, 2000 ). Likewise, a commitment to maturational theory also helps explain the delay in neuroscience to examine how the brain physically changes in response to environmental conditions, a line of inquiry that only began in the 1960s.

In addition to the theoretical pitfalls of nativism, Developmentalists point to numerous studies that show how some seemingly native behaviors and innate constraints on learning are driven by the experiences of animals. For example, the comparative psychologist Gilbert Gottlieb ( 1971 ) showed that newly hatched ducklings display a naïve preference for a duck maternal call over a (similarly novel) chicken maternal call (Gottlieb, 1971 ), even when duck embryos were repeatedly exposed to the chicken call prior to hatching (Gottlieb, 1991 ). It would be easy to conclude that ducklings have an innate preference to approach their own species call and that they are biologically constrained (contraprepared) in learning a chicken call. However, Gottlieb found that the naïve preference for the duck call stemmed from exposure to the duck embryos’ own (or other) vocalizations in the days before hatching (Gottlieb, 1971 ). Exposure to these vocalizations not only made duck maternal calls more attractive, but it hindered the establishment of a preference for heterospecific calls. When duck embryos were reared in the absence of the embryonic vocalizations (by devocalizing embryos in ovo ) and exposed instead to chicken maternal calls, the newly hatched ducklings preferred chicken over duck calls (Gottlieb, 1991 ). These studies clearly showed how seemingly innate, biologically based preferences and constraints on learning derived from prenatal sensory experiences.

For Developmentalists, findings like these suggest that nativist explanations of any given behavior are statements of ignorance about how that behavior actually develops. As Kuo and Lehrman made clear, nativist terms are labels, not explanations. Although such appeals are couched in respectable, scientific language (e.g., “X is due to maturation, genes, or heredity”), they argue it would be more accurate simply to say that “We don’t know what causes X” or that “X is not due to A, B, or C.” Indeed, for Developmentalists, the more we unpack the complex dynamics about how traits develop, the less likely we are to use labels like nature or nurture (Blumberg, 2005 ).

On the other hand, Developmentalists recognize that labeling a behavior as “learned” also falls short as an explanatory construct. The empiricist position that knowledge or behavior is learned does not adequately take into account that what is learned and how easily something is learned depends on (a) the physiological and developmental status of the person, (b) the nature of the surrounding physical and social context in which learning takes place, and the (c) experiential history of the person. The empiricist tendency to say “X is learned or acquired through experience” can also short-circuit developmental analyses in the same way as nativist claims.

Still, Developmentalists appreciate that classifying behaviors can be useful. For example, the development of some behaviors may be more robust, reliably emerging across a range of environments and/or remaining relatively resistant to change, whereas others are more context-specific and malleable. Some preferences for stimuli require direct experience with those stimuli. Other preferences require less obvious (indirect) types of experiences. Likewise, it can still be useful to describe some behaviors in the ways shown in Table 1 . Developmentalists simply urge psychologists to resist the temptation to treat these behavioral classifications as implying different kinds of explanations (Johnston, 1987 ).

Rather than treat nature and nurture as separate developmental sources of causation (see Figure 1 ), Developmentalists argue that a more productive way of thinking about nature–nurture is to reframe the division as that between product and process (Lickliter & Honeycutt, 2015 ). The phenotype or structure (one’s genetic, epigenetic, anatomical, physiological, behavioral, and mental profile) of an individual at any given time can be considered one’s “nature.” “Nurture” then refers to the set of processes that generate, maintain, and transform one’s nature (Figure 2 ). These processes involve the dynamic interplay between phenotypes and environments.

Figure 2. The developmentalist alternative view of nature–nurture as product–process. Developmentalists view nature and nurture not as separate sources of causation in development (see Figure 1 ) but as a distinction between process (nurture) and product (nature).

It is hard to imagine any set of findings that will end debates about the roles of nature and nurture in human development. Why? First, more so than other assumptions about human development, the nature–nurture dichotomy is deeply entrenched in popular culture and the life sciences. Second, throughout history, the differing positions on nature and nurture were often driven by other ideological, philosophical, and sociopolitical commitments. Thus the essential source of tension in debates about nature–nurture is not as much about research agendas or evidence as about basic differences in metatheoretical positions (epistemological and ontological assumptions) about human behavior and development (Overton, 2006 ).

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Nature vs. Nurture

Reviewed by Psychology Today Staff

The expression “nature vs. nurture” describes the question of how much a person's characteristics are formed by either “nature” or “nurture.” “Nature” means innate biological factors (namely genetics ), while “nurture” can refer to upbringing or life experience more generally.

Traditionally, “nature vs. nurture” has been framed as a debate between those who argue for the dominance of one source of influence or the other, but contemporary experts acknowledge that both “nature” and “nurture” play a role in psychological development and interact in complex ways.

• The Meaning of Nature vs. Nurture
• The Nature-vs.-Nurture Debate
• Identifying Genetic and Environmental Factors

The wording of the phrase “nature vs. nurture” makes it seem as though human individuality— personality traits, intelligence , preferences, and other characteristics—must be based on either the genes people are born with or the environment in which they grew up. The reality, as scientists have shown, is more complicated, and both these and other factors can help account for the many ways in which individuals differ from each other.

The words “nature” and “nurture” themselves can be misleading. Today, “ genetics ” and “environment” are frequently used in their place—with one’s environment including a broader range of experiences than just the nurturing received from parents or caregivers. Further, nature and nurture (or genetics and environment) do not simply compete to influence a person, but often interact with each other; “nature and nurture” work together. Finally, individual differences do not entirely come down to a person’s genetic code or developmental environment—to some extent, they emerge due to messiness in the process of development as well.

A person’s biological nature can affect a person’s experience of the environment. For example, a person with a genetic disposition toward a particular trait, such as aggressiveness, may be more likely to have particular life experiences (including, perhaps, receiving negative reactions from parents or others). Or, a person who grows up with an inclination toward warmth and sociability may seek out and elicit more positive social responses from peers. These life experiences could, in turn, reinforce an individual’s initial tendencies. Nurture or life experience more generally may also modify the effects of nature—for example, by expanding or limiting the extent to which a naturally bright child receives encouragement, access to quality education , and opportunities for achievement.

Epigenetics—the science of modifications in how genes are expressed— illustrates the complex interplay between “nature” and “nurture.” An individual’s environment, including factors such as early-life adversity, may result in changes in the way that parts of a person’s genetic code are “read.” While these epigenetic changes do not override the important influence of genes in general, they do constitute additional ways in which that influence is filtered through “nurture” or the environment.

Theorists and researchers have long battled over whether individual traits and abilities are inborn or are instead forged by experiences after birth. The debate has had broad implications: The real or perceived sources of a person’s strengths and vulnerabilities matter for fields such as education, philosophy , psychiatry , and clinical psychology. Today’s consensus—that individual differences result from a combination of inherited and non-genetic factors—strikes a more nuanced middle path between nature- or nurture-focused extremes.

The debate about nature and nurture has roots that stretch back at least thousands of years, to Ancient Greek theorizing about the causes of personality. During the modern era, theories emphasizing the role of either learning and experience or biological nature have risen and fallen in prominence—with genetics gaining increasing acknowledgment as an important (though not exclusive) influence on individual differences in the later 20th century and beyond.

“Nature versus nurture” was used by English scientist Francis Galton. In 1874, he published the book English Men of Science: Their Nature and Nurture , arguing that inherited factors were responsible for intelligence and other characteristics.

Genetic determinism emphasizes the importance of an individual’s nature in development. It is the view that genetics is largely or totally responsible for an individual’s psychological characteristics and behavior. The term “biological determinism” is often used synonymously.

The blank slate (or “tabula rasa”) view of the mind emphasizes the importance of nurture and the environment. Notably described by English philosopher John Locke in the 1600s, it proposed that individuals are born with a mind like an unmarked chalkboard and that its contents are based on experience and learning. In the 20th century, major branches of psychology proposed a primary role for nurture and experience , rather than nature, in development, including Freudian psychoanalysis and behaviorism.

Modern scientific methods have allowed researchers to advance further in understanding the complex relationships between genetics, life experience, and psychological characteristics, including mental health conditions and personality traits. Overall, the findings of contemporary studies underscore that with some exceptions—such as rare diseases caused by mutations in a single gene—no one factor, genetic or environmental, solely determines how a characteristic develops.

Scientists use multiple approaches to estimate how important genetics are for any given trait, but one of the most influential is the twin study. While identical (or monozygotic) twins share the same genetic code, fraternal (or dizygotic) twins share about 50 percent of the same genes, like typical siblings. Scientists are able to estimate the degree to which the variation in a particular trait, like extraversion , is explained by genetics in part by analyzing how similar identical twins are on that trait, compared to fraternal twins. ( These studies do have limitations, and estimates based on one population may not closely reflect all other populations.) 

It’s hard to call either “nature” or “nurture,” genes or the environment, more important to human psychology. The impact of one set of factors or the other depends on the characteristic, with some being more strongly related to one’s genes —for instance, autism appears to be more heritable than depression . But in general, psychological traits are shaped by a balance of interacting genetic and non-genetic influences.

Both genes and environmental factors can contribute to a person developing mental illness. Research finds that a major part of the variation in the risk for psychiatric conditions such as autism spectrum disorder, anxiety disorders, depression, and schizophrenia can be attributed to genetic differences. But not all of that risk is genetic, and life experiences, such as early-life abuse or neglect, may also affect risk of mental illness (and some individuals, based on their genetics, are likely more susceptible to environmental effects than others).

Like other psychological characteristics, personality is partly heritable. Research suggests less than half of the difference between people on measures of personality traits can be attributed to genes (one recent overall estimate is 40 percent). Non-genetic factors appear to be responsible for an equal or greater portion of personality differences between individuals. Some theorize that the social roles people adopt and invest in as they mature are among the more important non-genetic factors in personality development.

About one out of ten people is left-handed but the reasons why are not well understood. A new study now helps unlock the mystery of left-handedness.

A Personal Perspective: Facing the interplay between genetic factors and linguistic development prompted a question: Should I trust my instincts or those of others?

The latest findings on genetics reveals how genes may affect the risk for substance use disorders, and how they can help predict which treatment will work.

How do we make sense of new experiences? Ultimately, it's about how we categorize them—which we often do by "lumping" or "splitting" them.

How are twin studies used to answer questions related to the nature-and-nurture debate?

All I ask of strangers in the store—don't judge me as being less competent because my hair is grey and my skin well-textured. I’m just out doing my best, as we all are.

The new Biophilia Reactivity Hypothesis argues our attraction to the natural world is not an instinct but a measurable temperament trait.

A Personal Perspective: How can Adam Grant's newest book help OCD sufferers? In more ways than you think.

Do selfish genes mean that humans are designed to be selfish?

Are classical musicians more "craft" and jazz musicians more "creative"? A question for debate.

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Institute of Medicine (US) Forum on Neuroscience and Nervous System Disorders. From Molecules to Minds: Challenges for the 21st Century: Workshop Summary. Washington (DC): National Academies Press (US); 2008.

From Molecules to Minds: Challenges for the 21st Century: Workshop Summary.

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Grand Challenge: Nature Versus Nurture: How Does the Interplay of Biology and Experience Shape Our Brains and Make Us Who We Are?

Nature vs. nurture is one of the oldest questions in science. The answer is not an either/or, but rather it is both nature and nurture, acting in various degrees.

As summarized below in greater detail, many workshop participants—including Hyman, Marder, and Michael Greenberg, chair of the Department of Neurobiology at Harvard Medical School—chose to highlight the nature versus nurture question as one of the Grand Challenges of the field, but in so doing, they put a twist on the question, asking: How does the interplay of biology and experience shape our brains and make us who we are?

The key word there is “interplay.” “Interplay” suggests, and modern research in neuroscience demands, that there is a back and forth pattern between nature and nurture, a dynamic system that involves a continuous feedback loop shaping the physical structure of our brains.

• Brain Plasticity

Thirty years ago, the working assumption in neuroscience was this: People are born with a set number of neurons, hardwired in a certain way, and brain function is essentially all downhill from there. We spend our lifetimes losing connections and neurons—the brain slowly falling apart until we die.

Except it is not true. In 1998, Fred “Rusty” Gage, working out of the Laboratory of Genetics at the Salk Institute, showed that the human brain can and does produce new nerve cells into adulthood ( Eriksson et al., 1998 ). In mice, he showed that exercise could increase the rate of neurogenesis, showing that the system is not fixed, but responds itself to experience and the outside world. The discovery of neurogenesis and an improved understanding of neuroplasticity—the ability of the brain to shape, form, eliminate, and strengthen new connections throughout life—has completely recast the question of nature versus nurture.

“Neurons can change their connectivity,” explained Blakemore. “They can change the strength of their connections. They can change the morphology of their connections. They can do it not necessarily just in early stages of life, although that is especially exaggerated, but probably throughout life responding to new environments and experiences.”

New research shows, for instance, that the number and strength of connections we have in the brain is determined by how often those connections are stimulated. The brain, if you will, has a “use it or lose it” approach to neurological maintenance.

Genetic programming also plays a key role. In most cases, the initial formation of a synapse occurs independent of stimulation. But if that synapse is not used, the brain will “prune” or eliminate it. Conversely, the more often a connection is used, the stronger it becomes in a physical sense, with more dendritic spines connecting to one another and a stronger net connection over time.

On the developmental side, researchers now understand the critical role that sensory input plays in shaping the wiring of the brain from the earliest days. Blakemore discussed work in his lab on the development of neural wiring in mice. Researchers have known since the 1960s that the neurons connected to the ultrasensitive whiskers of mice align themselves in a format called “barrel fields.” Each of these barrel fields is connected to a single whisker, although how or why they influence function is unknown. Blakemore showed that if you removed a clump of whiskers at an early age, the segment of the brain linked to that area never develops the barrel structure.

Similar research has shown in mice that if you tape one eye shut from birth, the mouse never gains the ability to see from that eye—it needs the stimulation to develop. However, if you tape shut the eye of an adult mouse for a similar period of time, vision is not affected.

All this seems to point the finger toward experience, but of course, the system really works as a complete feedback loop.

“We used to think . . . that the capacity of the brain to change its connections was an entirely independent process from the genetic regulation of structure,” said Blakemore. “But, of course, that cannot be the case. If adaptive change is possible, that must be the consequence of having molecular mechanisms that mediate those changes. Plasticity is a characteristic that has been selected for, so there must be genes for plasticity.”

In the case of barrel fields, Blakemore’s lab and other investigators have identified a number of molecules and genes that appear to be involved in mediating between incoming information for the whiskers and the anatomical changes necessary to produce the barrel field.

Understanding how this interplay works has huge implications for understanding how our brain develops and changes over time, and raises a number of interesting questions. Marder, for instance, asked how the brain can be so plastic and yet still retain memories over time.

Plasticity, however, is just one half of the equation; the underlying genetics are critically important, and new techniques and technologies make this a particularly interesting time to address these questions. For instance, modern, high-throughput gene-profiling technologies allow researchers to figure out all of the underlying transcriptions in a neuron, and see how these are manifest in the body.

Understanding the interplay of biology and experience on learning and development will surely require understanding the biological processes that cause changes in individual neurons and synapses. But this is only part of the puzzle. We must also understand the control of learning processes at a system-wide level in the brain. How does the brain orchestrate the right set of neural synaptic updates based on training experiences we encounter over our lifetime? Given the tremendous number of synapses in the brain, it is unlikely that a purely bottom-up approach will suffice to answer this question.

A complementary approach to studying experience-based learning at a system level relies on machine learning algorithms that have been developed to allow robots to learn from experience, described Mitchell. One intriguing study has shown that temporal-difference learning algorithms, which enable robots successfully to learn control strategies such as how to fly helicopters autonomously, can be used to predict the neural activity of dopamine-based systems in the human brain that are involved in reward-based learning ( Schultz et al., 1997 ; Seymour et al., 2004 ; Doya, 2008 ). The integration of such system-level computational models alongside new research into synaptic plasticity offers an opportunity to examine the interplay of biology and experience on learning and development from multiple perspectives.

New tools will allow researchers to understand how variability between different genes and neurons and neuronal activity could influence behavior and capabilities across different people, the researchers said. Who we are is not only influenced by the yes/no expression of genes, but also the specific levels of expression among different genes, which in turn influences neuronal activity.

• Gene-Environment Interactions

Nature and nurture are not simply additive interactions that result in a particular behavior, but rather a complex interplay of many factors. Nature includes not only the usual factors—parents, homes, what people learn—but also many other factors that individuals are exposed to routinely in their daily environments. As Marder emphasized, we cannot simply assume that gene X produces behavior Y. Instead as Bialek described, there are often many additional factors that directly and indirectly interact with gene X and ultimately influence variants in behavior. These variants define individuality.

As previously described, it has been known for almost 50 years that experience from the outside environment shapes our brain. This comes initially from the original work of Nobel Laureates David Hubel and Torsten Wiesel who studied how information is sensed and processed in the part of the brain responsible for vision. As Greenberg commented, the field is now at a point where we could in the next 10 years attain a significant mechanistic understanding of how the environment impinges directly on our genes to give rise to a malleable organ that allows us to adapt and change.

• Huge Clinical Importance

Multiple participants at the workshop—including Nora Volkow, director of the National Institute on Drug Abuse; Joseph Takahashi, investigator of the Howard Hughes Medical Institute and Northwestern University; Lichtman; and Coyle—highlighted the role of genetics in shaping the brain as one of the fundamental challenges for neuroscience, both for its basic scientific interest and for its practical applications: Understanding how genes and experience come together to impact the brain could significantly alter how we think about treating neurological disease. Many of the most common neurological and mental health disorders—schizophrenia, bipolar disorder, autism, Parkinson’s disease, multiple sclerosis, Alzheimer’s disease—are complex genetic disorders that are influenced by environmental factors.

Alcino Silva, professor in the Departments of Neurobiology, Psychiatry and Psychology at the University of California, Los Angeles, showcased research from his lab showing he could treat and reverse developmental disorders in adult mice. This finding is worth repeating because it is so contrary to our general thinking on developmental disorders: Scientists working out of Silva’s lab have been able to reverse the impacts of the developmental disorder NF-1 (Neurofibromatosis type 1), which is caused by genetic malfunction, by treating the pathology of the disease in adult mice. These mice, which have obvious cognitive deficits, regain mental function when treated; Silva has advanced the study into human clinical trials.

The applications of this vein of study extend beyond developmental disorders. A growing body of evidence is revealing a massive feedback loop among genetics, neurological structure, experience, and disease. You are three times more likely to die from a heart attack if you are depressed than if you are not, for instance, and depression has a huge impact on diabetes as well, stated Coyle.

Taking a step backward, clinical data also show that people who experience multiple stressful episodes in their lives tend to suffer from clinical depression. But there is tremendous variation: Some people are resistant to stress and others are not.

“It turns out that the pattern is correlated with a polymorphic variation in one particular gene, the gene for the transporter for serotonin, a transmitter which is known to be involved in regulating mood,” explained Blakemore.

How do genes work in the brain to determine our resilience to stress, and how can those capabilities be monitored and modulated for better health?

• The Way Forward

Asking these kinds of questions was not realistic 10 or even 5 years ago. The advent of high-throughput gene profiling and the growing sophistication of our ability to manipulate genes in animal models lets us, for the first time, explore the role that genes play in both creating and modulating our neural structures. At the same time, new imaging techniques and technologies like channel rhodopsin “light switches” let us better characterize neural systems and their response to the world around us, and to begin to plumb the tremendous feedback loop among genes, experience, and the physical activity in the brain.

Until quite recently, these have remained philosophical questions, commented Marder. However, the field of neuroscience is now in a position—through all the molecular, connectomics, and technological advances—to put these questions on firm mechanistic, biological bases, and to attack them scientifically.

• Cite this Page Institute of Medicine (US) Forum on Neuroscience and Nervous System Disorders. From Molecules to Minds: Challenges for the 21st Century: Workshop Summary. Washington (DC): National Academies Press (US); 2008. Grand Challenge: Nature Versus Nurture: How Does the Interplay of Biology and Experience Shape Our Brains and Make Us Who We Are?
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Nature Vs Nurture Essay for Students and Children

500+ words essay on nature vs nurture.

The topic of nature vs nurture is always a great topic of debate among people. There are great men who did work hard to achieve great heights . But still, they are some people who didn’t work that hard yet still managed to be successful.

In other words, it is a debate between hard work and talent. In the grooming of a person, the nurturing is essential. However, still, there are some individuals who were never born in a great environment . Yet by their sense of knowledge and intellectualism created a special place in the hearts of people.

Nature has given us many things in life and one of them is talents. Either we are born as the only individual in our family or it is in our genes. Furthermore, nature plays a vital role in deciding the future of a child. Many singers in this era are born with beautiful voices. They did not need any nurturing. Their talent took them to heights they couldn’t even imagine.

For instance, some of the great legends like Lata Mangeshkar, Asha Bhosle, Kishor Kumar had soulful voices. Also, they were the ones who sang from their childhood days. They started their careers and became successful at a very early age. Moreover, they did not get much teaching but still are the legends of all time.

Apart from singing, there are other talents that nature has given us. Various scientists like Albert Einstein , Isaac Newton , Galileo Galilei, started their work in their teenage years. They had amazing intellectualism, because of which they got recognition in their entire world. Furthermore, these scientists did not get any mentoring. They did everything on their own. Because they had extraordinary intelligence and ambition in life.

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On the other hand, the nurturing of a person is important. Because hard work beats talent. With proper mentoring and practice, a person can achieve success in life. If a person has an environment in which everybody is in the same profession and are successful in it.

Then there is a great chance that the person will land up in the same profession and will achieve heights. Because in that environment he will get proper nurturing.

Furthermore, he will also be able to perform better over the years. “ Hard work always pays off ”. This idiom is always true and nobody can deny that. If a person has true dedication then it can beat talent. Various singers, dancers, musicians, businessmen, entrepreneurs did work really hard for years.

And because of that, they got recognition in the entire world. In these categories, musicians are who achieved heights only with their hard work and constant practice.

It is true that there are no shortcuts to success. Various known legends like Bob Dylon. Lou Reed, Elvis Persley, Michael Jackson worked hard throughout their lives. As a result, they were some of the great personalities in the entire world.

Q1. What is the meaning of nurture?

A1. Nurture means the way a person grooms himself. This is done in order to achieve success. Nurturing is essential in a person’s life because it can be a way a person can cross the barrier and do something great. Moreover nurture also means the mentoring and care a person is getting in an environment.

Q2. What is the difference between Nature and Nurture?

A2. The main difference between nature and nurture is, nature is the talent a person inherits from his parents or is God gifted. While nurturing is hard work and mentoring of a person in a particular field. So that he may excel in that field.

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21 Nature vs Nurture Examples

The nature vs. nurture debate is the long-standing argument over whether heredity (nature) or environment (nurture) plays a greater role in developing human characteristics and behaviors. 

Nature refers to the biological characteristics we are born with, including genetic predispositions toward certain traits. In contrast, nurture includes external influences that shape us, such as culture, relationships, and everyday experiences.

For example, when it comes to personality development, some people believe that genetics play a stronger role than environmental factors; this would be considered a nature-focused perspective. 

Others may view the environment as more important. In this case, a nurturing upbringing could help individuals develop their personalities. Therefore, both sides can have valid arguments for their respective positions in the debate.

The Nature Perspective

In the context of the nature vs. nurture debate, nature refers to biological heredity and genetic predispositions inherited by individuals from their parents at birth. 

Buheji (2018) states that:

“in the “nature vs. nurture” debate, nature refers to an individual’s innate qualities (nativism)” (p. 221).

This includes physical characteristics such as eye color, facial features, personality traits, and behavioral tendencies.

Genes determine the unique physical characteristics of each individual while also influencing psychological and social behavior.

Some research implies that roughly 50% of an individual’s personality and disposition are pre-determined by genetics (Bouchard & Loehlin, 2001).

However, Krueger and colleagues (2008) state that the interplay between gene-environment interactions has a consequential effect on one’s character traits. Hence, the heritability of personality isn’t always precisely 50%.

So, nature is the hereditary and genetic characteristics pre-determined at birth and influence a person’s behavior.

The Nurture Perspective

Nurture, in the context of the nature vs. nurture debate, is used to describe environmental factors that influence an individual’s development. 

According to Coon and Mitterer (2014), nurture:

“…refers to the sum of all external conditions that affect a person” (p. 100).

This includes a variety of influences such as parenting style, educational experiences, cultural background, and exposure to different environmental conditions over time.

While “nurture” may naturally invoke ideas of childhood and parental care, environmental components and life experience can shape human mental, emotional, and physical health throughout their lives (Harsha et al., 2020).

For example, lifestyle choices have been found to impact a person’s risk for developing certain diseases and their level of immunity against illness. 

Furthermore, addiction susceptibility can be impacted by environmental factors such as peer group that has been observed throughout an individual’s life (Ducci & Goldman, 2012).

Simply, nurture is an umbrella term for any environmental influences that shape the development of a person’s mental, physical, and emotional health. 

Examples of Nature vs Nurture

Nature examples.

• Eye color : A person’s eye color is determined by their genetic makeup and inherited from their parents.
• Height : As with eye color, height is a physical trait that is determined by a person’s genes and largely determines an individual’s adult height.
• Risk of D iseases : A person’s risk for developing certain diseases can be partially attributed to their genetic predisposition for that illness and influenced by lifestyle factors and personal environment.
• Immune S ystem F unctionality : Genetic predisposition plays an important role in determining an individual’s resistance to disease through the strength of their immune system. However, lifestyle choices can also influence this trait over time (e.g., diet and exercise).
• Hair Color: Hair color is determined by genetic factors. Recessive genes, like the red hair gene, generally have to be present in both parents for the recessive gene to become dominant.
• Balding: Going bald is an inherited trait. Some groups – such as male British Anglo-Saxons – are more likely to go bald in their 30s than the average.
• Adrenaline response : An individual’s ability to react quickly in dangerous situations—their “fight or flight” response—tends to be innate in all of us.

Nurture Examples

• Ethics and Parenting style : An individual’s upbringing and the parenting style they are exposed to can shape their behavior, emotional reactions, and psychological outlook throughout life.
• Linguistic Determinism Theory : In this theory, the language we are taught as a child will determine the ways we think and interact with the world. It goes some way to explaining how people of differing language groups may have differing values and belief systems .
• Values and Cultural background : Depending on their cultural background, different individuals may be exposed to different values and belief systems, which can impact their attitudes toward certain issues or topics/ideas/beliefs.
• Anxiety and Exposure to T rauma : Experiences with violence or traumatic events can have long-term effects on an individual’s psychology which could manifest outwardly as symptoms of anxiety or difficulty coping under pressure in later stages of life.
• Positivity and Social E nvironment : The people an individual interacts with can either positively or negatively affect their development. Individuals need to surround themselves with positive influences while avoiding those that might lead them down the wrong path in life.
• Relationship E xperiences and Sense of Security : Positive relationships throughout a person’s life will tend to improve outlook and well-being. In contrast, unhealthy relationships could leave long-term psychological damage that might need professional help before it can be addressed adequately by an individual suffering firsthand.

Nature and Nurture Examples

• Personality traits: The role of genetics (nature) in determining personality traits, such as extraversion or conscientiousness is balanced against the influence of upbringing and life experiences (nurture).
• Aggression: There is debate over whether aggressive behavior is primarily influenced by genetic factors (nature) or by environmental factors, such as upbringing, social learning , and exposure to violence (nurture).
• Athletic ability: The role of genetics (nature) determines a lot of our natural talent in sports but the importance of training, motivation, and exposure to physical activity (nurture) takes us the rest of the way.
• Musical talent: Musical ability may be affected by genetic predisposition (nature) but also environmental factors, such as exposure to music at a young age, education, and practice (nurture).
• Attachment styles: It is debatable whether a person’s attachment style (secure, anxious, or avoidant) is impacted by genetics (nature) versus the influence of early childhood experiences and caregiver relationships (nurture).
• Empathy and emotional intelligence: The capacity for empathy and emotional intelligence is debatably determined by both genetics (nature) and the result of upbringing, social exposure, and life experiences (nurture).
• Spiritual beliefs: Theological determinism holds that god has pre-selected his chosen people who will be true believers (nature) while others think that belief in god is a choice and we must raise our children to maintain a belief in god (nurture).
• Learning styles: In the 1980s, there was extensive debate over whether preferred learning styles, such as visual, auditory, or kinesthetic, are determined by genetic factors (nature) or influenced by educational experiences and personal development (nurture). Today, most education theorists believe that learning preferences are based on nurture over nature.
• Addiction susceptibility : Scientists have identified genes related to addiction susceptibility, even though this trait is also heavily influenced by the environment (Ducci & Goldman, 2012).
• Intelligence : Education can significantly impact traits such as intelligence levels and knowledge base, with certain experiences inspiring curiosity or creativity in individuals later in life.

Origins of Nature vs. Nurture Debate

The debate surrounding the extent to which human development is influenced by nature (heredity) or nurture (environmental factors) has been around since ancient times.

Plato, the renowned Greek philosopher, argued that beneficial traits in humans were attributable to both nature and nurture. He believed people could adapt to external occurrences throughout their lifetime (Englander, 2010).

However, his mentor Socrates leaned more towards genetics as the primary factor of human development – a notion known as Nativism, which was coined by both philosophers together.

In the late 1800s, Charles Darwin’s theory of evolution and Sir Francis Galton’s article “Hereditary Talent and Character” sparked a resurgence in interest in this topic (Galton, 1865)

So, Galton (1865) suggested hereditary influences to be at least as important as the environment when determining an individual’s outcomes in life.

The debate continued through subsequent decades, with psychologist John B. Watson’s revolutionary suggestion that environment—what he called “nurture”—was more important than hereditary factors or biology (Herrnstein, 1998).

In recent years, researchers have realized that both internal (genetic) and external (environmental) factors play a role in how individuals develop physically and psychologically. 

As such, most experts now subscribe to an approach that looks at how both genetic inheritance and environmental influences work together throughout life to shape each person’s unique character traits and behaviors.

The Role of Epigenetics in the Nature vs. Nurture Debate

Epigenetics is the study of changes in gene expression caused by environmental factors, such as diet and exposure to toxins, without altering the underlying sequences of DNA .

It is an emerging field of research that has been gaining prominence in recent years as scientists try to uncover how and to what extent the environment can shape genetic expression (Harvard University, 2019).

Epigenetic influences are now considered a significant factor in the nature vs. nurture debate, particularly in how individuals develop physically and psychologically throughout life. 

Evidence suggests that epigenetic mechanisms can be used to modulate gene expression depending on the environment, thus having a direct influence on an individual’s characteristics and behaviors (Harvard University, 2019).

This means that while both genetics and environment may play a role in determining an individual’s outcomes in life, epigenetics provides an additional layer of complexity by allowing environmental factors to interact with gene expression.

Nature vs. nurture is a decades-old debate that continues to be studied in various fields. 

Nativists state that genetics play a major role in determining characteristics and behaviors. For example, a person may have inherited certain traits from their family. 

However, empiricists suggest that external factors, such as upbringing and lifestyle choices, can also have a significant influence.

From ancient philosophers to modern-day scientists, this debate has gone through various iterations and continues to evolve today with the introduction of epigenetics. 

More recently, epigenetics have emerged as a key factor in the debate. Its  mechanisms can be used to modulate gene expression depending on the environment, thus having a direct influence on an individual.

So, it appears that both nature and nurture are important factors in determining an individual’s outcomes in life. 

Bouchard, T. J., & Loehlin, J. C. (2001). Genes, evolution, and personality.  Behavior Genetics ,  31 (3), 243–273. https://doi.org/10.1023/a:1012294324713

Buheji, M. (2018).  Understanding the power of resilience economy . Mohamed Buheji.

Coon, D., & Mitterer, J. O. (2014).  Psychology: A journey . Wadsworth/Cengage Learning.

Ducci, F., & Goldman, D. (2012). The genetic basis of addictive disorders.  Psychiatric Clinics of North America ,  35 (2), 495–519. https://doi.org/10.1016/j.psc.2012.03.010

Englander, M. (2010).  The nature and nurture of learners . AuthorHouse.

Galton, F. (1865).  Hereditary talent and character . University of Bristol Library.

Harsha, N., Ziq, L., Lynch, M. A., & Giacaman, R. (2020). Assessment of parental nurturing and associated social, economic, and political factors among children in the West Bank of the occupied Palestinian territory.  BMC Pediatrics ,  20 (1). https://doi.org/10.1186/s12887-020-02317-0

Harvard University. (2019).  What is epigenetics? The answer to the nature vs. nurture debate . Center on the Developing Child at Harvard University; Harvard University. https://developingchild.harvard.edu/resources/what-is-epigenetics-and-how-does-it-relate-to-child-development/

Herrnstein, R. J. (1998). Nature as nurture: Behaviorism and the instinct doctrine.  Behavior and Philosophy ,  26 (1/2), 73–107. https://www.jstor.org/stable/27759383

Krueger, R. F., South, S., Johnson, W., & Iacono, W. (2008). The heritability of personality is not always 50%: Gene-environment interactions and correlations between personality and parenting.  Journal of Personality ,  76 (6), 1485–1522. https://doi.org/10.1111/j.1467-6494.2008.00529.x

Viktoriya Sus (MA)

Viktoriya Sus is an academic writer specializing mainly in economics and business from Ukraine. She holds a Master’s degree in International Business from Lviv National University and has more than 6 years of experience writing for different clients. Viktoriya is passionate about researching the latest trends in economics and business. However, she also loves to explore different topics such as psychology, philosophy, and more.

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Nature Vs Nurture in Psychology

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