The dangers of biological determinism

There probably are biological differences between groups of people, but the moral cost of making the wrong assumptions should keep us skeptic.

Ariel Pontes
May 8, 2015 · 12 min read

I’ve always been a zoology lover. I grew up watching Animal Planet and comparing the behavior of humans to that of other animals. I ended up not pursuing a career in the area, but reading and watching video-lectures about biology has been one of my oldest and most constant hobbies. I am a fan of Darwin, Dawkins, Frans de Wall and Sapolsky. I always try to find the biological origins of human social behavior and, although I recognize both sides of the nature vs. nurture dilemma, I must admit I have a bias towards the former when it comes to personal interest and curiosity. Lately, however, I’m a bit disillusioned. I’ve noticed that many still rely on factoids of the field to defend racist and sexist claims, the inevitability of certain social hierarchies and the maintenance of the status quo, sadly causing many on the other side to, as a defense mechanism, reject behavioral biology altogether. But is it really the case that by giving credibility to this science we inadvertently give basis for these supremacist and deterministic arguments? Is to reject it altogether really the only solution?

Programmed to adapt

Natural selection is the process by which gene pools change their composition in response to environmental pressures. If the weather in a certain region starts getting colder, the subgroups of a given species that have thin coating will die out and the subgroups with thicker fur will replace them. But humans are not polar bears or camels. We thrive in the north pole, the Amazon rainforest and the Sahara desert. And as a social species, the relevant environmental forces at play include not only lifeless elements like the weather, but the social community itself. This being the case, it is easy to see that evolving to be flexible and respond dynamically to changes in society and the environment is advantageous.

This responsiveness involves a whole system of biological communication mechanisms that works as an interface between our organism and the environment. This goes from macro structures such as our sensory organs to micro structures such as non-coding sections of DNA that trigger gene expression as response to changes in the chemical composition of its surroundings (I’ve written about it in more detail here). In school level material, the DNA is often compared to a recipe. If you read more about it, however, you realize it is a very bad comparison. It is bad because it fails to illustrate its dynamic, interactive role. If anything, the DNA is like the instruction sheet for a complex game. A set of rules that, while constant, yields infinite results depending on the unpredictable conditions of a match.

A pseudo-dilemma

This being the case, when we read news about “genes responsible for X”, we have to keep in mind how gene expression mechanisms work. 98% of the DNA is non-coding, meaning they don’t code proteins, but serve regulatory functions. This is a sign that a great deal of our complexity is not related to how perfectly generated the end proteins are, but how good our communication system is. How well our body interacts with the environment. And this should be no surprise. All living beings depend on a level of responsiveness to the environment to its survival, and a brief observation of social structures across regions and history reveals that humans are a great example of a species that succeeded in becoming highly flexible and adaptive. Perhaps, in fact, this is what best distinguishes us from other animals. How could we manage this with a rigid input-output system, insensible to subtle external changes?

With all this in mind, if we stop to think about it, we see the classical nature vs. nurture dilemma is not as clear as we thought. Maybe the best answer to this dilemma is another question, one traditionally attributed to Donald Hebb:

“Which contributes more to the area of a rectangle, its length or its width?”

A man may be born with a vasopressin receptor that predisposes him to polygamous behavior, but he may be raised in a traditional religious family in the 19th century and have an arranged marriage at age 18. Another may be born with one that predisposes him to monogamy, but may grow up in the 21st century in the company of teenagers who compete for females as a symbol of power and status and end up adopting a polygamous behavior because of peer pressure. It is very hard to draw a line between what is genetic and what is environmental.

This type of example tends to be described as instances of “culture overriding biology”. Although I can concede this expression may be useful for the sake of simplicity, it is worth noting that it is not 100% accurate. You can always look at it as the biological tendency to conform to social norms overriding the biological tendency for a given mating strategy. In the end, everything boils down to biology. If multiple biological tendencies competing with each other inside an individual seems confusing, I suggest reading a bit about the gene-centered view of evolution.

A working definition of “natural” and “cultural”

In spite of all this, I would be lying if I said these words serve no purpose whatsoever. There are indeed behavioral tendencies that are harder to change through culture than others. Overcoming fear, repulsion or laughter completely, for example, and creating an entire society of cold, fearless people is probably impossible even with the most rigid policies and extreme educational strategies. Family structures and strategies for raising children, on the other hand, vary greatly across cultures, from tribes raising children collectively to extended families in India and nuclear families in 20th/21st century Western societies. In order to avoid confusion, I will try to explicitly separate two ways in which the terms “natural” or “biological” are usually used in the context of behavior:

  1. A virtually immutable behavioral pattern like responding to fear, that is present not only in all human cultures but in several of our ancestor species and is probably impossible to change.
  2. A dominant behavioral pattern that is not universal but that appears to be the “default” one, being also the most usual across all cultures throughout history, a possible example being men spend relatively little time compared to women raising and bonding with children, with exceptions being somewhat rare (e.g. the Aka tribe ¹).

As for the term “cultural”, I will define it as:

  • Any alternative behavioral pattern that appears to not be the “default” one. It may be a secondary one, such as the Aka tribe example where fathers spend a large amount of time taking care and developing physical intimacy with the offspring to the point of letting the babies suck their nipples when the mom is not around, or it may have come to be a primary one even though anthropologically recent, such as the nuclear family ².

We shouldn’t fight against natural differences

This argument has been used throughout history and is still used today to criticize attempts to give equal rights, equal social status or to otherwise empower vulnerable or subordinate groups in society.

“That the African Negro is destined by Providence to occupy this condition of servile dependence is not less manifest. It is marked on the face, stamped on the skin, and evinced by the intellectual inferiority and natural improvidence of this race. They have all the qualities that fit them for slaves, and not one of those that would fit them to be freemen.” — Governor George McDuffie, Speech to the South Carolina Legislator, 1835

“A woman’s brain evolves emotion rather than intellect; and whilst this feature fits her admirably as a creature burdened with the preservation and happiness of the human species, it painfully disqualifies her for politics.” — Dr. William Hammond, 19th century brain specialist commenting on the Women’s suffrage movement

“We have some natural, physiological problems of criminality within some of the Romanian communities, especially among Romanian citizens of Roma ethnicity.” — Teodor Baconschi, 2010, then Minister of Foreign Affairs in Romania

Although more rarely used to oppose defenders of racial equality nowadays, it is still often used to criticize proponents of gender quotas or any affirmative action or differential treatment in general aiming to achieve greater gender equality. I am not suggesting that an ideal society should eradicate inequality completely, or that anyone who believes some level of inequality is healthy is no better than an anti-abolitionist of the 19th century, but too often the line of reasoning used is indeed the same, and it relies on fundamentally flawed premises:

1. Science can tell whether a given trait is biological or not

Everything we know about reproduction, Darwinism and evolutionary pressures leads to the inevitable conclusion that males and females will, to some extent, evolve different behavioral tendencies. Granted. But are these biological differences immutable or just dominant? Unlike most animals, humans, through complex communication and the ability to accumulate knowledge and transmit customs, gave rise to a myriad of different cultures and societal structures. Again, one of our most distinctive characteristics compared to other species is our flexibility and our capacity to adapt in response to our surroundings, not as a species through millennia of evolution, but as individuals through socialization and enculturation. It is to our evolutionary advantage to have as few immutable behavioral tendencies as possible.

This makes it very hard to argue, given any specific behavioral difference observed between sexes, that it is natural and not cultural, even though our models strongly suggest that some tendencies must indeed be intrinsic. Let’s start by examining dominant patterns. The only way to scientifically determine whether a difference is naturally dominant or cultural is by isolating children from birth and studying the societal structures that arise. Plus, in order to control for environmental differences, we would have to grow these isolated children in many different environments. We would probably need something like several islands, with different climates and ecosystems. Then we would have to do this several times, with several generations of children and see if the difference under inspection was consistently maintained in different environments for most groups of children.

After this, maybe we could have a certain level of confidence that this behavioral tendency is innately asymmetrical for different sexes, races or whatever it is we’re comparing. We still couldn’t be sure because it is impossible to simulate all imaginable environments. Plus, the degree to which us humans alter the environment is so profound that we are constantly creating brand-new environments that were unimaginable to those a few generations before, and behavioral patterns that have not even been alternatives for millions of years within a few decades can become the norm in most of the industrialized world. There are many forces in nature that can drive the adoption of one or other behavioral pattern. In the book Guns, Germs and Steel (adapted to a 3 part documentary by National Geographic), Jared Diamond explores many of these forces and provides a fascinating picture of how certain populations flourished and developed into highly technological societies while others remained in small bands of hunter-gatherers without ever going through an agricultural revolution. None of his arguments rely on the premise that there are innate, biological differences between these populations.

2. Natural differences can’t be erased

This brings us to immutable differences. If it is pretty much impossible, for all practical purposes, to be sure about whether a certain behavioral difference is naturally dominant or not, what can we expect from immutable differences? It is an absolutely extraordinary claim to suggest a given behavioral pattern found in present day society is inevitable and that no matter how society changes in the future this pattern will always be preserved. To imply such a thing reveals a deep historical blindness. A brief exploration of the field of anthropology vividly illustrates how much of what we take for granted as norms vary greatly across cultures and are historically recent. It is extremely hard to argue that something simply can’t change. As Carl Sagan put it:

“Extraordinary claims require extraordinary evidence”

3. It is relevant to know whether a behavior pattern is biologically dominant or not

If we can never be sure whether a difference is naturally dominant, let alone immutable, and if anthropology shows us most behavior patterns are flexible, than it’s basically irrelevant to ask whether this difference is natural or not in the context of a discussion about policy and social change (in the context of scientific curiosity it’s always valid).

So what is relevant?

As should be no surprise, discussions about policy and social change always boil down to ethics and justice. The question is not whether something can change or not. It probably can, and even if it can’t, nobody can prove so, therefore focusing on it is fruitless. The question is whether the present arrangement is just or not. Blacks, Roma, Aboriginals, Amerindians, women and other groups for all sorts of anthropological reasons are all to some degree still excluded in many of the societies they live in. They have less economical power, are underrepresented in the government, in leadership positions, the media, and many overrepresented in prisons. Does this sound just?

Harald Eia, in the Norwegian documentary Brainwash: The Gender Equality Paradox is perfectly justified in criticizing the radical cultural-determinists he interviews, who say absurd things that can hardly be interpreted such as “biology doesn’t influence behavior”. He goes on, however, to suggest that biological differences between the sexes lead men to prefer systemizing jobs and women empathizing ones. It may be true, it may not be. In any case it is perfectly legitimate to discuss the hypothesis scientifically.

What is unfortunate though, is that Eia seems to not realize the danger of his suggestions and how they have served as ammunition for the oppressive elites of the past. The truth is, however hard you may wish it wasn’t the case, science influences ideologies, and by pretending it doesn’t we risk legitimizing great injustices again and again. When is it going to be enough? When one makes certain claims public, it is imperative that a note be added with important safeguards. By not giving sufficient attention to the issue, the documentarian seems to imply that the current gender-based division of labor is just. Is it? Well, overall, it clearly isn’t. Regarding empathizing vs. systemizing jobs only? I don’t know. But I do know one thing: it is not by ruminating on whether it is “natural” or “cultural” that we will find an answer.

Recognizing that something may be the biological norm among humans doesn’t mean it’s unchangeable and doesn’t make it morally unquestionable. Murder is natural. Rape is natural. Infanticide is natural. War is natural. Still few would go as far as publicly opposing humanity’s efforts towards peace. Why, then, oppose efforts towards equality?

A history of bad mistakes

“Compare then the blessings enjoyed by Spaniards of prudence, genius, magnanimity, temperance, humanity, and religion with those of the little men [the Amerindians] in whom you will scarcely find even vestiges of humanity […] How can we doubt that these people — so uncivilized, so barbaric, contaminated with so many impieties and obscenities — have been justly conquered?” — Juan Gines de Sepulveda

Throughout history people have assumed, in the absence of adequate evidence, that certain differences were impossible to overcome. The results were catastrophic. Now in the 21st century it continues to happen. In the end it seems to me that if there’s something that is a clearly dominant characteristic of human beings is to resist change. But however hard it may be to believe it, the world is actually changing for the better ³.

It could be true, in principle, that Roma people have “physiological problems of criminality”. It could be true that women overall are just not natural leaders and are biologically unsuitable for politics. But 200 hundred years ago blacks were believed to be incapable of flourishing as freemen, now there are blacks ruling the most powerful nation in the world and getting NASA awards and many others for their work in astrophysics. Women were not even allowed to vote in the beginning of the last century and now they rule the biggest economiy in Europe and in Latin America, respectively. So what basis do we have to insist that subordinate groups in society are naturally so? It is simply safer and wiser to assume, in the absence of sufficient evidence, that they are not.


We will probably never know beyond any doubt, for any behavioral pattern, whether it’s “natural” or “cultural”. There is a big danger in assuming some people are biologically predestined to remain in a subordinate position in society and it is evidenced by a history of social exclusion, slavery and genocide. It is much safer to simply assume the reverse. In fact I can see no danger in it. One does not, however, need to deny powerful models in evolutionary biology for ideological reasons. I hope I have provided sufficient arguments to make it clear that this approach is unnecessary and anti-scientific. If somebody is using scientific models to justify conservative ideals and the subjugation of underprivileged groups, the blame should be on them for not using science properly, not on the models themselves. Biological determinism is nothing more than conservative pseudo-science. I close this text with the words of one of these great people who belong to a group that was once believed to be biologically inferior and incapable of producing the minds that it now produces thanks to social change:


  1. ^ Are the men of the African Aka tribe the best fathers in the world?
  2. ^ Social change and the family
  3. ^ OK, Haters, It’s Time To Admit It: The World Is Becoming A Better Place
  4. ^ Neil deGrasse Tyson
  5. ^ Angela Merkel
  6. ^ Dilma Rousseff

Originally published at on May 8, 2015.

Humanist Voices

Official Secular-Humanist publication by Humanist Voices

Humanist Voices

Official Secular-Humanist publication by Humanist Voices

Ariel Pontes

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Secular-humanist, M.A. in analytic philosophy, volunteer at @YoungHumanIntl, blogger at Support me at

Humanist Voices

Official Secular-Humanist publication by Humanist Voices