Steve Stewart-Williams on the value of evolutionary psychology

August 26, 2020 • 10:15 am

When I give talks about why Americans reject evolution so frequently, I refer to Steve Stewart-Williams’s excellent book from 2010: Darwin, God, and the Meaning of Life: How Evolutionary Theory Undermines Everything you Though You Knew.  It goes through reason after reason why evolution not only undermines our ideas, but why that undermining makes people resistant to evolutionary biology and its conclusions. It explained to me, for instance, why 27% of American Catholics are creationists, embracing Biblical literalism despite the fact that the Church itself explicitly accepts evolution. Those people, like many, just can’t get past the naturalistic and non-human-centric implications of evolution. The book is like a bucket of cold water tossed on the idea that evolution doesn’t conflict with religion.

Steve has a newer book, published in 2018 (click on screenshot below to go to Amazon site). I haven’t yet read it, though it’s coming to me through my library, but it’s apparently a discussion of the evolution of culture (“evolution” that’s both genetic and cultural), as well as a discussion of the merits of and problems with evolutionary psychology.

 Stewart-Williams is an associate professor of psychology at the University of Nottingham Malaysia Campus, and I’ve written about some of his work here, describing why he thinks that the difference between human males and females in levels of aggression has a substantial evolutionary basis.  But, as the interview below shows, in which he speaks with Pablo Malo at the site La Nueva Ilustración Evolucionista (“The New Evolutionary Enlightenment”), Stewart-Williams doesn’t accept whole hog all the claims of evolutionary psychology, and is sometimes quite critical of them. In other words, Stewart-Williams’s attitude towards the discipline is similar to mine. Read the interview by clicking on the screenshot below. There’s an English translation so you don’t have to use Google translate except for the introduction (or if you speak Spanish):

Stewart-Williams’s take on evolutionary psychology also differs from that of biologists on the “progressive” left who reject evolutionary psychology as a whole, dismissing it as a farrago of “just-so stories” and untested (and untestable) hypotheses. You can see this attitude, for instance, in people like blogger P. Z. Myers, who should know better, and his minions. Yes, the discipline has its “soft underbelly,” as I’ve described, but it’s also led to informative insights, and simply cannot be swept away with unwarranted ridicule. Dismissal of evolutionary psychology as a whole (see another dismisser below) comes not from a scientific attitude, but an ideological one: if human behavior evolved over millions of years, just like human bodies and physiology (one can’t deny the latter), then perhaps we are partly slaves to biological determinism, and, worse, behavioral differences between men and women might be in part the result of evolution.

I think the evidence for evolved differences is pretty solid, but blank-slaters, who happen to populate the progressive Left, deny this determinism because they mistakenly think that evolved differences somehow imply moral differences. As Steve Pinker showed in his book The Blank Slate, and I’ve said many times, the idea that evolution tells us what is right and wrong is a fallacy—the “naturalistic fallacy”.

But I digress. I’ll just say once more that the blatant dismissal of evolutionary psychology as a discipline is not only unwarranted, but ignorant and ideologically based. To think that human bodies are the product of evolution but human minds are not can only be the product of some overweening and blinkered ideology.

On to the interview. It’s in both Spanish and English.. I’ll highlight the main points in bold, and any quotes from Steve will be indented:

Some of evolutionary psychology is weak and “silly”, and can comprise “just-so stories”. 

A third reason I decided to write Ape was that I wanted to present a somewhat circumspect view of evolutionary psychology – one that met the critics halfway on a number of issues. This includes the common criticism that evolutionary psychologists too often overextend the adaptationist mode of explanation, seeing adaptations in all sorts of psychological and behavioral tendencies that probably aren’t adaptations at all. My response to this criticism is: Guilty as charged. Evolutionary psychologists have sometimes put forward some pretty silly adaptationist hypotheses, and we need to be a bit more careful about that
But a lot of it is sound, though not “proven”—but of course no science is “proven”. We just accrue more or less confidence in hypotheses as we do more tests. So the declarations of people like philosopher Subrena Smith, who declared that doing evolutionary psychology was “impossible”, are badly mistaken. (I discussed Smith’s paper here, and Steve Pinker’s ideas about it here.) 

Evolutionary psychology certainly isn’t perfect, but I have to say I wasn’t particularly impressed with [Smith’s] critique. The idea that that EP is impossible – not just difficult, but impossible – strikes me as so extreme that I’m a little surprised so many people took it so seriously. It also strikes me as awfully convenient that, of all the sciences, the one we can rule out a priori, on purely logical grounds, just happens to be one that many people dislike and object to for explicitly political reasons.

Smith’s argument is basically a sophisticated reboot of the old retort that “behaviour doesn’t fossilize.” She claims that there’s ultimately no way to show that the psychological tendencies underpinning people’s behaviour today evolved in prehistoric times to perform the same functions that they currently perform, and thus that evolutionary psychology is impossible in principle.

Is she right? Well, one reason to doubt that evolutionary psychology is impossible is that… people are already doing evolutionary psychology: They’re gathering evidence bearing on evolutionarily informed hypotheses, and this evidence nudges up or down our confidence that these hypotheses are accurate. Sure, no one has provided evidence that proves any hypothesis in evolutionary psychology with the certainty of a mathematical proof. But that’s true of every claim in science. Scientists can only ever nudge our confidence up or down. Perhaps this is harder in EP than in some fields (although the replication crisis in psychology and elsewhere suggests that it’s not as easy as we thought in any field). But saying that it’s harder is very different than saying that it’s impossible.

And in some cases, it isn’t even particularly hard. Consider hunger. Strictly speaking, we can never say with 100% certainty that this psychological capacity evolved in our prehistoric ancestors, or that it had the same function back then as it does today (i.e., motivating us to seek and consume food). But it seems reasonable to think that it did. Indeed, it seems unreasonable to think otherwise – unreasonable, in other words, to think that our ancestors did not experience hunger or that the primary function of hunger back then was unrelated to eating. And if you accept that, I think you also have to accept that there’s no in-principle reason to reject any and all evolutionary psychological hypotheses, even if others are more difficult to evaluate. For a more detailed response to Smith’s paper, see Ed Hagen’s excellent post on the topic.

Few evolutionary psychologists now accept two views they’re often accused of: “Massive modularity” (the brain comprises various semi-independent modules that code for different behaviors), and the “Environment of evolutionary adaptedness”: the idea that our behaviors all show adaptations to the life of our ancestors on the African savannas. The latter, at least, would be foolish given the evidence that humans have undergone palpable evolutionary change in the last 10,000 years. Stewart-Williams prefers that evolutionary psychologists just analyze human behaviors using well-established evolutionary principles like kin selection, parental investment, reciprocal altruism, and the like.

Refutations of the “Cinderella Effect”: the demonstration that parents are more brutal toward their stepchildren than their biological children, are weak. (These were mostly raised by Hans Temrin.) According to Stewart-Williams, the data come down pretty much in support of the Cinderalla Effect. If further studies buttress those data, it would be good evidence for an evolutionary-psychology explanation based on relatedness and parental investment. It makes sense that you’d treat your biological children better than those unrelated to you, and you might even abuse the latter if it favors the prospects of the former. (Remember, lions that invade a pride immediately kill all the cubs from the mothers, and then inseminate the mothers, yielding cubs that are related rather than “step-cubs”.)

The idea of memes hasn’t been that productive in understanding human cultural evolution, but there are a few suggestive examples of memes evolving simply because they have self-propagating characteristics. One of these examples involves witch hunts, and was published last year by Hofhuis and Boudry. I haven’t read it yet, but I’ve been a pretty severe critic of “memetics.”

The Himba people of Namibia have a 48% rate of non-paternity; that is, half the children in a family aren’t fathered by the “father.” Isn’t that a refutation of evolutionary theory? Stewart-Williams explains why we’d sometimes expect these anomalies.

Disparities in representation of males vs. females in different areas don’t always demonstrate sexism and bigotry, as many assume. They could just be differences in preference, and perhaps some of these are the result of evolved behaviors. I’ve made this point many times before, but it still goes over the head of many “progressives”, who fail to realize that there is, for many cases of unequal representation, a competing hypothesis to the idea of “structural discrimination.”

Here’s what Steve says about that in response to a question:

What are you working on now? What mystery would you like to unravel next?

I’m working on two main projects at the moment. One is a theoretical paper with Lewis Halsey, looking at the causes of gender disparities in STEM. As everyone knows, men outnumber women in certain areas of STEM, including mathematics, computer science, and physics. As everyone also knows, the most common explanations for the gender gaps are discrimination and socialization. We argue, in contrast, that although discrimination and socialization are part of the story, they’re not the whole story. We make two main claims in our paper. The first is that factors other than discrimination contribute to gender gaps in STEM; these include, in particular, average sex differences in interests and life priorities. The second is that these average differences aren’t due entirely to socialization. Socialization plays an important role, but the differences are also partly inherited.

People sometimes assume that if you admit a role for biological factors in shaping STEM gender gaps, you must think nothing should be done about those gaps. But that’s not our view. We are wary of overly coercive fixes, such as offering people monetary or other incentives to make career choices they wouldn’t otherwise make, and affirmative-action policies that, in effect, discriminate against men and lead people (including the benefactors of such policies) to secretly wonder whether they really earned their success. But that doesn’t mean we should do nothing. We should let young people know about all the science careers on offer, and make clear that these are options that women as well as men should consider. We should make sure we highlight the scientific achievements of both sexes, rather than focusing unduly on men. We should encourage people to accept and support women (and men) who make gender-atypical choices. We should put policies in place that reduce the possibility of bias against either sex, including gender-blind evaluation of job applications, research grants, and the like. And we should do what we can to make science careers compatible with the demands of motherhood (and fatherhood).

Having done all that, though, we should respect the choices that people make about their own lives and careers, even if this doesn’t result in perfect gender parity. In other words, we should aim for equality of opportunity, rather than equality of outcome. People are ultimately going to be happier if they pursue the careers that most interest them.

There’s a lot more to the interview than this, so if you want a level-headed take on evolutionary psychology, I’d recommend that you have a look at the interview, and perhaps read Steve’s latest book.
Steve Stewart-Williams



38 thoughts on “Steve Stewart-Williams on the value of evolutionary psychology

  1. Much of the discussion of differences between men and women in STEM aims to support a story of discrimination against women. But since women and men participate in higher education in similar proportions, it is obvious that if more women choose for example to become veterinarians then fewer will choose physics.
    Also in our university at least the balance in science is close to 50:50, but biomedicine and pharmacy is predominantly female and physics mostly male.

    1. The strength of women in certain STEM fields like veterinary women seem good examples that differences in interests and priorities are part of the reason for gender disparities.
      There is also the ‘other hand’ of the issue, which is discovered when one asks why fewer men go into certain fields nursing or teaching children. These too are because of various factors but among them are interests and priorities.

  2. It’s hard as a lay person to keep up with changes in the field.

    I was under the assumption that the brain does have a “modular” structure. For example, my husband had a stroke four years ago that led to very specific, permanent deficits due to infarction in regions of the left temporal and left occipital regions.

    1. I can’t answer with full authority, but sensory perception and control of motor functions is pretty modular, and importantly those locations are consistent from brain to brain.

      1. I should have made clear that his deficits are a permanent cut in his right visual field and an inability to recognize words. “Sensory,” as you say.

      2. How could it not be modular to some extent? The neurons that connect to our eyes are surely part of a visual module. Similarly for other senses. Same for our muscles. The question is really a matter of how far the modularity goes and how it is structured.

        1. I think I said this has modularity. For example, with vision there is of course the visual cortex which is a large area on the back of the bran that maps 1:1 with what you are looking at. There are also nearby ‘association areas’, which are fascinating. These are areas (I don’t know how sharply demarcated) that store memories about things that you sense. There are association areas for vision, touch, and hearing, and so on. Perhaps these are not as modular as they were thought to be. I don’t know.

          1. Modularity implies a partitioning along one or more dimensions. At this point, we don’t even know what dimensions even exist. For example, we can only track visual images into the first couple of neuronal layers, AFAIK. After that, we have no idea what any of it means. We see spiking but don’t know if information is carried in the frequency, the amplitude, or whatever. I believe this is a problem even for our analysis of the simplest neural networks.

            The location of memories isn’t known well at all. We can find things like the famous “Jennifer Aniston” neuron but it is hard to know what to conclude from them. Scientists certainly have made conclusions but they really have no idea whether they’re right.

            Neuroscience is an area where the theorizing is way out ahead of what can be known with much certainty. Theories can develop with lots of details and large groups of adherents but they’re almost entirely based on guesswork. It is as difficult to prove a theory correct as it is to prove it wrong. I think we have to take anything we hear or read with a grain of salt.

    2. In a PsychoLinguistics concentration done 50+ years ago, I read a lot of studies on aphasia and saw some mild evidence of modularity: In one case a WWI vet had learned German as an undergrad and been head-wounded. His German was stored in an undamaged area; he was able to regain American English facility by using German. In contrast, Welsh and Swiss miners who had language aphasia from head injuries were shown to have stored multiple languages in the same places in the cerebral cortices. Another study was about a USA vet who’d lost his color sense from a head wound. He was an artist, so this was serious. He was trained to paint and draw with his left hand instead of his right; his color sense was recovered as the undamaged hemisphere came to dominate.

  3. “I think the evidence for evolved differences is pretty solid, but blank-slaters, who happen to populate the progressive Left, deny this determinism because they mistakenly think that evolved differences somehow imply moral differences.”

    I think the Progressive Left take a “blank slate” position because if the slate wasn’t blank, anything on it can be used to fight their agenda. In short, it doesn’t serve their purpose. We live in an era when it’s quite fashionable to ignore inconvenient truths or evidence. Everyone seems to be doing it.

    1. But sexuality and gender are somehow baked in (genetically based) so conversion therapy, for instance, is considered to be barbaric – as if anyone has a choice. I have not heard how the blank-slaters explain that apparent discrepancy in their model.

      1. I don’t think they try to explain it as it would just get in the way of pursuing their agenda. I suppose it is a bit like trying to convince religious people that God doesn’t exist. You won’t convince many but if it sparks doubt in a few, it should be considered a victory.

      2. “But sexuality and gender are somehow baked in” This seems to be an important part of the trans activist view that medical and surgical alteration of a person’s physical sex is the only appropriate way to treat gender dysphoria, and that the person’s internal identification with the other sex is the immutably important aspect not to be altered (e.g., by psychological or psychiatric treatment). So I think the progressive view is that the slate is blank but tilted severely in a particular direction at birth and the tilt should not be altered or questioned. Sorry if ’tilt’ is not a good metaphor. Reminds me of ‘charm’ and other words to refer to qualities of subatomic particles.

  4. While it is difficult to establish a genetic basis for many behavioral commonalities, which could easily be copied and learned, the evidence for the genetic basis of many behavioral abnormalities, such as ASD and stuttering, is overwhelming. Why should it be difficult to accept that genes play an important role in human behavior? Apart from ideological reasons, I mean.

    1. And, btw, stuttering is a good example of how blank slatism (is that a word?) can lead to cruelties. How many poor stutterers have been punished endlessly in vain attempts to change their behavior? In school, one of my teachers used to embarrass and sometimes rap the knuckles of my friend, who was a stutterer. (I grew up in harsh times.)

  5. Looks like a really interesting book… I might try to get this as an audiobook.

    I do think the flexibility in the expression of human behavior is interesting and worth learning about, although I think blank slaters have this concept backwards – I think this is a new and emerging skill in mammal brains that we should figure out how to cultivate, not the default state that we should figure out how to clear away environmental stimulus for. Flexibility of cognition and behavior is, usually, a good thing, but I think it has to be cultivated.

    I think what is interesting about humans (and some other social mammals and also some birds,) is the ability to seemingly understand conceptual, vs. rote, categories of behavior. Behaviors like “helping”, “cleaning”, “punishing”, “preparing”, etc. – these are behaviors that we seem wired for but that we can also update to very different forms depending on the context. For example (apologies, I am about to blasphemy here,) if a cat wants to “help” you, it will rely on a fairly stereotypical behavior like grooming or bringing you a dead mouse. If a social animal such as a d*g wants to “help” you, they seem to have at least a rudimentary understanding of what that might mean in a context-dependent way. They are not blank slates, by any means, but they do have relatively more ability to respond to the environment in that particular case. I think understanding how that works and where our adaptability of response is rooted and comes from could actually help us think about how to cultivate it, while assuming it must 100% be there from birth actually hinders this.

    1. No blasphemy here. Dogs are a good example, as humans applied the selective pressure, and dogs evolved to please humans and be helpful. Cats, on the other hand, evolved to elicit help and affection from their staff.

      1. I think cats like to help in their own way… in the absence of mice, I know some cat owners (self included,) say their cat will ‘hunt’ down socks, toys, etc., and leave them by their bed.

        What I think is interesting is wondering how this would be coded if say, writing a computer program. It seems to me that “Let help = bring stupid human who is a bad hunter dead animal” would be straightforward. It’s an A=B type situation. But something must shift when you change it to “Let help = make human happy [environment + what human wants + … etc.]).

        1. Both my cats “helpfully” bring me their puffballs all the time, yowling all the while, and sometimes depositing them in the water bowl shared with the perplexed dog.

    2. Re dogs I especially love the examples of convergent evolution of other morphological and behavioral traits in silver foxes that were domesticated recently in large part by artificial selection for willingness to have close contact with the fox farmers. Selection for these behaviors led to other traits including floppy ears (as in many domestic dog breeds) that were not subject to selection but are apparently genetically correlated with the response to selection for friendly fox behavior.

      1. I remember seeing that as well! Not sure why those traits would be linked except that perhaps they are all more common in baby foxes?

  6. I confess, I am a fully paid up member of the evolutionary psychology squad!

    The dunnock (Prunella modularis) is like those people – they copulate secretly with other individuals. The balance of probability is I suppose that if you do not bring up your offspring someone you know will. So it works in a small group & the most fertile males will be the most successful. I, on the other hand, am a failure of evolution!

  7. Maybe a route to “break” the denialism of those who reject all evo psych research is to bring up less triggering examples. Rather than try to defend hypotheses about gender differences or male aggression, for example, one could instead get them to at least admit that things like wanting to eat and drink are probably behaviors that evolved. Or agreeing that there are behaviors that look a lot like kin selection, so maybe, just maybe, one could reluctantly admit that human pair bonding and cooperative child rearing might be the result of natural selection.
    Start there, and see how far down the rabbit hole you can go.

  8. The Ape that Understood the Universe is a provocative title. I’ve often marveled at how the few genetic differences between us and the other great apes had such a profound effect.

  9. Social constructionism cannot entirely account for the resistance to Evolutionary Psychology. For example, they know that certain disabled or ill people would not survive long on their own, some wouldn’t make it a few minutes. If we applied the naturalistic fallacy the way they (allegedly) fear, severely disabled or ill people would not be let alive. That cannot be the reason alone. To perhaps a significant degree the Evolutionary Psychologist smells differently than humanities scholars. Here are some possible reasons:

    First, they are like the storm troops from the dreaded STEM that invade academic turf. Grants, prestige and influence are at stake, and perhaps the fear that STEMs more empirical approach might make the humanities or “studies” subject obsolete in the eyes of the financiers or the public.

    Secondly, disciplines in the humanities enjoy a hegemony over large areas that are deemed difficult already. The anthropologist or social scientists assumes they can cover their area good enough. Admitting Evolutionary Psychology would complicate it enormously. Crucially, it’s a complication from an entirely different domain. Here, their intensive, lifelong studies of the works of Derrida and Foucault in original french are useless, and they suddenly have to put up with Darwin, Hamilton and the likes, or bother with mathematical game theory. They worry that their study of French might turn out a waste of time (yes, I’m polemical, but many studies subjects share a very similar foundation, and evolutionary biology is really different from that).

    Third, by preloading that Evolutionary Psychology are merely “just so” stories, they defang the reputation of STEM empiricism. The people who fund the post-structuralist corners of academia might just continue to back the “just so” stories they are know and appreciate.

    Fourth, these Evolutionary Psychologists are often seen adjacent to consumer research. They are bloody capitalists out to give more powers to marketing departments and advertising.

    And fifth, I think they share a similar sentiment as the religious. The idea that people’s mind may be shaped by messy evolutionary forces is disenchanting and reduces the human spitit to something icky biological and quasi-mechanical. The feeling alone is important, not the rationalisation. That bad feeling goes double for certain corners in humanities academia, becauce this “reductionism” also smells of the earlier days when science was overtly wedded to racism, war and imperialism.

    Other than that, the book mentioned above sounds a lot like Harari’s Sapiens, which I read recently (I recommend it).

  10. I may be wrong about this, but my recollection is that much of the wholesale rejection of evolutionary psychology can be traced to arguments and studies from the 1990sabout the adaptive significance of rape. The cultural reaction to those studies (sorry I can’t remember them and can’t be arsed to dig them up right now) was the naturalistic fallacy writ large: rape is awful, but things that are adaptive are inherently good, so rape can’t be adaptive. It didn’t help that the arguments were made (again if I recall correctly) in a way that was clumsy and lacking in the kind of throat clearing about is versus ought that one would expect a sensible person to include when writing about these things.

    1. I played a major role in criticizing those “adaptive rape” arguments, which were made by Thornhill and Palmer (I had one review of their book in Nature with Andrew Berry and another by myself in the New Republic.) My criticism of their hypothesis was based on the data they used to support it, not on a genera dislike of the field, though at that time I was far less enthusiastic about evolutionary psychology than I am not (they’ve made progress).

  11. Good timing for me, I just happen to be looking for a book, EV being of interest,
    Robert Plomin’s “Blueprint” research on SNP’s their consequent future influence on behaviour AND prediction using polygenic scores seems like a natural partner for EV, or at the very least, help each other out.
    My understanding of brains, modules, etc, is it is very highly interconnected, e.g. visual input can also be tagged by emotions, two separate parts encoding a memory. It is why something visual can upset or delight say. Why it can remain as a visual memory longer than perhaps it should, especially if it’s a traumatic experience. It can, provoke a sense of nausea in the gut, all stemming from the brain. A sense of disgust has an evolutionary origin, such as eating rancid foods, hygiene? picking parasites off the body…
    Bugger it, if NS can input all that instinctual behaviour into the wild and natural world and if you don’t believe we are a “special” animal then EV is valid so long as you don’t blow your brains out with it.

  12. The Catholic Church does not officially oppose evolution, but still says that God created the first human. The problem now is that we have no idea what was that Original Sin that made God so angry? Did Adam eat an apple? That’s silly. Did he have sex with Eve? We wouldn’t exist if he didn’t. WHAT DID HE DO?

  13. Thank you, Jerry. Looks like another book to go on the list. It might be reductionist of me to put it this way, but it strikes me that people who believe that evolution has shaped the behaviours of all species except for H. sapiens have some explaining to do. Just as unlikely, it seems, is the belief that evolutionary pressures have made us all develop in varying ways in different parts of the world, affecting all our organs except, they say, for our brains. Differences are not a bad thing. Variety is life’s insurance policy; some will survive when conditions change suddenly. I’m of the opinion we should enjoy and celebrate our variety, rather than pretend we are really the shuffling clones of a Langian Metropolis, especially if that uniformity would make the work of the social engineers creating the next disastrous utopia easier.

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