Nature and Nurture

Excerpts from Key Readings


“Nature versus nurture is a long-standing debate in biology and society about the balance between two competing factors which determine fate: genetics (nature) and environment (nurture). The alliterative expression “nature and nurture” in English has been in use since at least the Elizabethan period[2] and goes back to medieval French.[3]

The complementary combination of the two concepts is an ancient concept (Ancient Greek: ἁπό φύσεως καὶ εὐτροφίας).[4] Nature is what people 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, experience and learning on an individual.” 


 These excerpts provide a jump-start into the deep waters of a persistent question:  

“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.”  (from Psychology Today)

The following excerpts reflect the politicized time in which they emerged, but the questions predate contemporary politics and will persist… At various levels of organization –from cells to societies– beliefs (sometimes implicit) about the relative influences and interactions of evolutionary and developmental processes play a huge part in sorting out the paths of cause and consequence that enable us to act in ways that meet our biological needs as individuals and as cultures.

Tiffany O’Callaghan reporting in New Scientist (2019) asks : are we asking the wrong question? 

Trouble is, this nature vs nurture debate is fundamentally wrong-headed. Even before conception, our make-up is influenced by “epigenetic” factors: choices our parents make, chemicals they are exposed to, infections they get. These don’t alter our genetic code, but just how the instructions it contains are carried out – how it is expressed. Environmental factors continue to change how our genes make us tick throughout life.” (Read more about why-its-time-to-call-time-on-the-nature-vs-nurture-debate)

Kim Hill and Robert Boyd (2021) commenting on findings that “adaptation to local ecological conditions is an important determinant of variation in human behavior in traditional societies:”  (format slightly adapted)

“Culture and genes are linked in a tight coevolutionary embrace, and this leads to complex patterns of genetic and cultural co adaptation. For example, Henrich has recently argued (12) that the extent to which people are embedded in networks of kin obligation is a function of 

  • ecological factors (cooperative intensive agriculture) and
  • cultural history (church edicts against kin marriage and collective property institutions),
  • and variations in the intensity of kin-network embeddedness [that] ultimately transformed human psychology into that observed today in “WEIRD” (Western, educated, industrialized, rich, democratic) societies, where individualism is paramount, rather than the psychology of traditional societies, where collectivism and kin-group favoritism predominate.

Experiments show that the cognitive, emotional, and psychological effects of these different cultural histories are profound, and imply that findings from Western modern societies may often be irrelevant to predicting behavior in non-Western and traditional societies. Likewise, the spread of monogamy in modern societies, despite increasing wealth stratification, appears to be a puzzle that requires both adaptive modeling (13) and a recognition that monogamous social norms substantially increased cooperation with societies, and this norm can spread by group competition and cultural imitation (12). Coevolution between genes and culture in different ecologies may lead to uniquely human patterns not anticipated by animal studies. These examples illustrate just how complex human behavioral studies will become when the social sciences fully integrate an adaptive evolutionary view with a view of human behavioral variation in terms of cultural social norms. So far, a complete theory that predicts when culture will override fitness maximizing ecological adaptation and vice versa is not available. That will be the challenge for the next generation of social scientists, as an “either/or” view is replaced with an integrated evolutionary theory of human behavior.” (excerpt from Hill & Boyd 2021)



Steven Pinker (2004) about the inevitable persistence of the question:..

 “A common position on nature and nurture among contemporary scientists can be summarized as follows:

 No one today believes that the mind is a blank slate; to refute such a belief is to tip over a straw man. All behavior is the product of an inextricable interaction between heredity and environment during development, so the answer to all nature-nurture questions is “some of each.” If people only recognized this truism, the political recriminations could be avoided. Moreover, modern biology has made the very distinction between nature and nurture obsolete. Since a given set of genes can have different effects in different environments, there may always be an environment in which a supposed effect of the genes can be reversed or canceled; therefore the genes impose no significant constraints on behavior. Indeed, genes are expressed in response to environmental signals, so it is meaningless to try to distinguish genes and environments; doing so only gets in the way of productive research.

 The attitude is often marked by words like ‘interactionist,’ ‘developmentalist,’ ‘dialectic,’  ‘constructivist,’ and ‘epigenetic,’ and is typically accompanied by a diagram with the labels ‘genes,’ ‘behavior,’ ‘prenatal environment,’ ‘biochemical environment,’ ‘family environment,’ ‘school environment,’ ‘cultural environment,’ and ‘socioeconomic environment,’ and arrows pointing from every label to every other label.


This doctrine, which I will call holistic interactionism, has considerable appeal. It is based on some unexceptionable points, such as that nature and nurture are not mutually exclusive, that genes cannot cause behavior directly, and that the direction of causation can go both ways (for example, school can make you smarter, and smart people are most engaged by schooling). It has a veneer of moderation, of conceptual sophistication, and of biological up-to-dateness. And as John Tooby and Leda Cosmides have put it, it promises “safe conduct across the politicized minefield of modern academic life.”

 But the very things that make holistic interactionism so appealing should also make us wary of it. No matter how complex an interaction is, it can be understood only by identifying the components and how they interact. Holistic interactionism can stand in the way of such understanding by dismissing any attempt to disentangle heredity and environment as uncouth. As Dan Dennett has satirized the attitude: “Surely ‘every- one knows’ that the nature-nurture debate was resolved long ago, and neither side wins since everything-is-a-mixture- of-both-and-it’s-all-very-complicated,  so let’s think of something else, right?” (Pinker 2004:7)[i]



 George Barlow (1991) on the Nature-Nurture debates:  

“The central problem in the history of animal behavior has been the inability to perceive the phenotype as the result of an interaction between genome and environment, despite the considerable lip service paid to the interaction. In North America the comparative study of animal behavior was overshadowed by the growth of an experimental psychology that produced the general-process view of learning, holding that the mechanisms underlying learning are much the same in all species. That made evolution irrelevant. During the same period ethology emerged in Europe as the study of naturally occurring behavior in an evolutionary context. Because evolution is fundamental to ethology, the genetic basis of behavior was a central precept. Ethology and psychology collided after World War II. After a vigorous exchange on the issues, a synthesis by Robert Hinde materialized, one that advanced the study of behavior and produced a sophisticated understanding of nature and nurture. A few decades later sociobiology appeared and was immediately assailed for making what were seen as unwarranted extensions from animal to human behavior, and for emphasizing genetic control of behavior. Much of the debate that ensued was distractingly political and threw little light on the scientific merits of the issues although it moderated the stance of sociobiologists; on the other hand, the politically inspired debates may have harmed the field of animal behavior.” (Barlow 1991)[ii]

The complete essays are available to read




[i] Pinker, Steven (2004) Why nature & nurture won’t go away. Dædalus Fall 2004: 5-17. https://www.amacad.org/publication/why-nature-nurture-wont-go-away


[ii] Barlow, George W. (1991) Nature-Nurture and the Debates Surrounding Ethology and Sociobiology. American Zoologist 31(2):286-296 URL: http://www.jstor.org/stable/3883406



Commentary from NEW SCIENTIST (2019)

Why it’s time to call time on the ‘nature vs nurture’ debate

How much of our make-up is predetermined by our genes, and how much by our environment? The truth is that we’re asking entirely the wrong question

By Tiffany O’Callaghan 11 December 2019


IT IS an age-old debate that crops up everywhere from discussions of gender identity to our propensity to conditions such as obesity. How much is hardwired inside, the inescapable product of our genes, and how much is down to external factors?

Trouble is, this nature vs nurture debate is fundamentally wrong-headed. Even before conception, our make-up is influenced by “epigenetic” factors: choices our parents make, chemicals they are exposed to, infections they get. These don’t alter our genetic code, but just how the instructions it contains are carried out – how it is expressed. Environmental factors continue to change how our genes make us tick throughout life.

For developmental psychologist Alison Gopnik at the University of California, Berkeley, this constant interplay makes even asking how much we are nature and how much nurture meaningless. “People often think about it as if there’s some kind of formula you could use,” she says. “That’s fundamentally misguided.”

In some cases, identical twins grow up to have dramatically different personalities, while in others identical siblings separated at birth turn out to have strikingly similar personalities, mannerisms and more. Even some genetic disorders can be thought of as environmental. Phenylketonuria, for example, inhibits a body’s ability to break down the amino acid phenylalanine, and can cause devastating brain damage. But if the disorder is identified at birth, children can go on to live happy, healthy lives, by taking supplements and adopting a low protein diet. “In one sense, this syndrome is 100 per cent nature, in another it’s 100 per cent nurture,” says Gopnik.

That isn’t to say genes mean nothing. With very large data sets, we do see trends between our DNA and particular characteristics and behaviours: certain genetic profiles give you a higher risk of being obese, for example, or affect your musical ability or even your likelihood of practising hard to realise your musical talent.

Behavioural geneticist Robert Plomin of King’s College London is a proponent of this “genome-wide polygenic sequencing” technique. His group’s research has suggested that more than 50 per cent of children’s performance at school is down to genetics, for instance. “Educational achievement is highly heritable,” he says.

Gopnik is more circumspect about such general conclusions. Genetic determinism has been used to justify campaigns of eugenics during some of the darkest chapters of history. That is why Plomin is also clear. “Heritability does not mean immutability, it does not mean innate, it does not mean determinism,” he says. “It’s probabilistic, it increases your risk for something.”

Miriam Mosing at the Karolinska Institute in Stockholm, Sweden, echoes the point. A particular gene profile represents at most a predisposition, she says. “It’s not a determinant, it’s not a pregnancy test – it would be like telling you that you’re 40 per cent likely to be pregnant.”

Having even bigger data sets will allow us to unpick these complex interplays with more certainty. More than 26 million people have now done at-home genetic tests. The UK government recently proposed plans to sequence every British child’s genome at birth, and Finland is working to sequence its entire population.

That’s an ethical and privacy minefield, but with the insights gleaned, we might end up beating both nature and nurture to live healthier, longer lives.”