Evolution is overrated

People love a good evolutionary narrative. I wouldn’t be able to count the number of times I’ve heard “back in our evolutionary past, it would have been useful for [insert some vague nonsense about how humans used to do things]”.

Somewhere along the line, evolutionary theories went from a useful way to fix psychological theories, to a generator of some of the most superficially idiotic.

And I think, reading between the lines, we can find a new use for them. But first, let me convince you that evolutionary narratives usually aren’t worth the reel they’re recorded on.

¶When evolutionary narratives are useful

Modern psychology is only about 120 years old. It graduated from something that was largely philosophy into something that was more experimental around the 1900s. And when it was still young, the philosophical roots were still strong.¹

Philosophy can just as easily be fruitless, as fruitful, because you can’t always just think your way to the right answers. And the slow integration of evolutionary ideas into the discipline of psychology is a very good example of that:

Professor Martin Daly put it very succinctly:

The reason why psychologists have wandered down so many garden paths is not that their subject is resistant to the scientific method, but that it has been inadequately informed by selectionist thought. Had Freud better understood Darwin, for example, the world would have been spared such fantastic dead-end notions as Oedipal desires and death instincts.

Adding evolutionary theory into our accounts of human behaviour helped us narrow them from the apparently plausible to the actually plausible.

So, there for example, Daly is referring to Freud’s idea that we all have unconscious urges towards self-destruction—the so-called death drive. The reason that so much of Freud’s thinking has been absorbed and improved in later psychological thought, is because it was thoughtful and sensible. The reason that death drives are mostly ignored outside of certain psychotherapy lounges is because it’s not particularly sensible. In particular, it doesn’t make any particular evolutionary sense. Having a force “whose function is to assure that the organism shall follow its own path to death” isn’t really a sensible feature of evolutionary selection. And instead, the aspects of the human experience Freud was seeking to explain are far better understood in terms of trauma responses and mechanisms for coping with existential anxieties. Things that (messily) keep people alive in the face of hardship, not drive them to death.

As a kind-of broad-spectrum filter for bad ideas, evolutionary theory has been very useful in this way. But more recently, evolutionary theory has started to go the other way. From filtering out the bad ideas, to filtering in different bad ideas. And that’s because it’s being used sloppily.

You see, for an evolutionary narrative to be more useful than simply filtering out implausible ideas, it actually needs to meet a number or criteria. It’s not enough to just come up with a neat evolutionary story, you need to also work out:

1. the mechanism (the what) - what causes or triggers the behaviour?
2. the ontogenic (the how) - how does this thing develop over the lifespan? How does it translate from DNA to behaviour? Is it learned, or innate?
3. the phylogenetic (the when) - when did this behaviour begin in the species? Is it phylogenetically recent (e.g. a feature of mammals) or distant (e.g. a feature of even invertebrates)?
4. and all of the above are clues to the functional (the why) - what are the ultimate reasons for this behaviour’s existence? What purpose does it serve?

And you know this thoughtful kind of process isn’t what’s happening, because most people say shit like “in our past, it could have been useful for humans to [something], and that’s why today we [something vaguely related and often distasteful they’re trying to justify]”.

This kind of thing barely covers the functional, never mind the other three that are supposed to precede it. It’s just an example of the primary critique of evolutionary psychology.

¶The “Just-So” story

Evolutionary narratives are often called ‘Just So’ stories. Named after Rudyard Kipling’s decreasingly iconic bedtime stories, the idea is that evolutionary narratives can be created to explain anything.

So, in Kipling’s How the Leopard Got His Spots, Kipling tells a story about how leopards once had a plain, sandy coat, but found they wanted to blend in with the shadows, so they asked a hunter to dab spots on its skin. This is how the leopard got its spots. But, you could easily tell another story about how the leopard got it’s spots. Maybe it slipped in some mud, or maybe it got sprayed by an elephant. You get it.

Evolutionary narratives often seem to have this same ‘it could be anything’ quality about them. You know, you might ask why giraffes have long necks. It could be because their ancestors found better food higher on the trees. But it could also be that longer necks made them more deadly in the odd combat giraffes get stuck into. And so on.

And you find this a lot. A lot of the really popular evolutionary narratives online try to explain to us why men and women are so different. You’ve probably come across the reels. Beards were a signal of [something something protector] and that’s why women love them. Red lips help emphasise [something something babies] and that’s why men love it. These things just hack our brains. You know. Science.

Some of the most popular are all David Buss’ sexual strategies stuff. This is, very roughly, the idea that men want fertile women and are scared of sexual but not emotional infidelity, where women want resource and status rich men but are scared of emotional and not sexual intimacy. You see, we’ll be told, men want babies, but they don’t want to waste resources on other peoples’ babies. Women want resources to help them make babies, and don’t want those resources spent on other women.

If you haven’t come across something that riffs off Buss, then you will. People love it. And, to be fair, David Buss really went out of his way to try to demonstrate how these trends seem to appear across many cultures and many times.

But there’s another evolutionary narrative that’s completely at odds with it—the egalitarian polygamist account. The idea there is that at our roots we were once egalitarian hunter-gatherers, and this extended to how we made and raised babies. Truly, it took a village to raise a child, and the oddly specific jealousies of Buss’ only came after the agricultural revolution. And the trends that support that narrative also seem to appear across many cultures and many times.

And the point here isn’t to litigate the two. The point is that any evolutionary narrative is going to be subject to exactly this kind of thing. Multiple possible explanations, because evolutionary history is a long fucking time, and no one can go back there to work out which narrative is the better one.

¶Why they’re interesting, and why they’re not

I was writing the article, the other day, about how the old behavioural economist notion of bias is a bit silly. You might have heard of some of these. Confirmation bias, availability heuristics, groupthink, negativity bias, etc etc. The problem, as I write about there, is that:

fundamentally, if you’re trying to predict what biases people are going to engage in, you’re stuck panning through hundreds of the fuckers. As one economist puts it, imagine you’re trying to help granny plan her retirement: what biases is she going to suffer from?

Will they be loss averse? Present biased? Regret averse? Ambiguity averse? Overconfident? Will they neglect the base rate? Are they hungry? From a predictive point of view, you have a range of countervailing biases that you need to disentangle.

Not a good tool for predicting behaviour.

This is true of evolutionary narratives too. You could tell almost any story you like about why humans are the way they are today. But which one is actually going to predict how we’re going to be?

You take our examples from earlier—are people more likely to prefer rich men and wide-hipped women as Buss would have it, or are they likely to end up being more promiscuous in relationships as the egalitarian account would have it? Well, both. They both work to explain features of modern relationships, but not enough to make plans. And also, they both fall down in the most important way. It turns out that what people want most of all is warm, kind, emotionally intelligent partners above any of these weird evolutionary things. So maybe there’s some third narrative that makes that finding work.²

Not very helpful for prediction. But, like biases, evolutionary narratives are an extraordinarily satisfying tool for explaining our behaviour. You see people doing things, and you can come up with any number of evolutionary narratives to explain it. As I point out:

this is even worse news for prediction, because it means you can’t work out when you’re likely to be right or wrong.

Sure, you can come up with an evolutionary story for anything a person does, but what are the chances that narrative has any bearing on what will happen?

But we don’t always need to predict stuff. Sometimes we just like to explain stuff. In fact, the sociology of the interesting suggests that explaining stuff like this is exactly what we find most interesting:

the most successful theories are those that subvert our weakly held beliefs. The hot-takes on things we don’t care very much about. If our strong beliefs are attacked, then we’re likely to resist the attack. If our existing beliefs are confirmed, we’re likely to do little more than nod and forget. But if the knowledge we don’t care about very much is revised, then it becomes interesting.

Evolutionary narratives are endless—I can ‘revise’ your weakly held beliefs about anything. Even other evolutionary narratives.

¶Evolutionary stories say more about Sally

Have you heard that phrase ‘what Sally says about Sarah says more about Sally than Sarah’? This is what evolutionary stories do. They tell you much less about how the world is, and much more about how the person telling you wants the world to be.

I wrote an article ages ago, about one of the core threads of the evolutionary narratives. This idea that atavism will solve our problems. You know, we were born to live in the woods or the plains or whatever, and the closer we get back to nature, the better we’ll be. This sits underneath diet fads and exercise fads and anti-corporate lifestyle fads and really anything that you’ve seen come with an ‘evolutionary narrative’ tagged to it. And it’s an amusing one because it’s:

something of a paradox. The assumption lies somewhere along these lines:

1. Humans have access to physical and mental resources we don’t necessarily use and a kind of extraordinary flexibility to thrive. From Siberia to the Sahara, we can dominate almost any biosphere. So we should take advantage of those resources and put them to work rather than withering away behind our desks.
2. But of course, the reason we’re doing that is because we have been taken out of some ideal environment (i.e. the wilderness) and placed into another context (i.e. the modern world). All of a sudden, that unique robustness we were talking about becomes a fragile, brittle thing, prone to shattering under the attendant pressures of modern life.

Are humans robust or not? To say they are robust in some contexts and not in others implies that, in fact, they are not robust but are rather sensitive to changes in the environment.

And I go on to talk about how we haven’t yet found any conclusive evidence to suggest that life was much better or worse for us ‘back then’, than now.³ But also, we know that humans lived under remarkably diverse conditions across time and place.

People using this ‘evolutionary’ thread aren’t actually identifying anything about how the world once was, and how it informs us today. They’re telling us that they don’t like that they feel unhealthy, or that they’re stuck behind a desk, or that they wish they had more time for nature. That they see a different life than the one they’re living, and they want to be there.⁴

The people all hung up on sexual evolution and evolutionary mating habits are also easy to read. They don’t like how hard it is to get people into bed, or harder, into a marriage. They want an instruction manual. And in particular, they want an instruction manual that tells them that they can seduce their lovers in a way that means they won’t feel ashamed of giving in to the social pressure that informs us what it is to be a man or a woman. Whatever you think of the nature/nurture thing around gender-norms,⁵ no sane person is going to argue that our social infrastructure heavily taxes people who deviate from our cultural norms around these things. And if you secretly like those norms, but are worried people will make fun of you for that, then evolutionary theory suddenly makes it feel scientific instead. Who could argue with that?

I’ll give one more example, before I close. People are really excited about neurodivergence online. I joke about this a lot with a friend of mine, because much of the online content is just stuff that normal people find hard and has nothing to do with unusual brains (measurably true, not just anecdotal). Basically, it’s just trendy to be neurodivergent. And one of the reasons for this is because it was once evolutionarily necessary. Can you believe it? You’ll find people saying the ADHD was an adaptation for nomadic hunters who needed to be bright and jumpy and alert, as opposed to farmers who could afford to be patient while tending to their crops. Or, Autism is some neolithic remnant of a need to apply special systematic or particularly technological thinking to advance human survival. Not everyone is cut out to the quiet, hermetic frontiers, but our austists might be.

And what I don’t want to do here is argue against the narrative. Not the ADHD hunters and the Autistic survivalists. Not the gender essentialists trying to connect their experience with the mysterious forces of nature. Not the unhealthy people who wish they had a life with more dirt and sun.

It’s almost certain that evolution played a role in all of these things, and maybe it’s exactly as they tell it. But you’ll never convince me of that. You’ll never convince me even of the evolutionary theories I prefer. Evolutionary theories can only ever filter theories out. They’ll never be useful tools for filtering theories in. Not without time-travel. So don’t be convinced yourself. Just view them for the information they do contain—any time you see someone parrot an evolutionary theory of behaviour, you’re getting a unique look inside that person’s head. A vision of the world as they wish it to be. And if you aren’t reading a psychology blog to learn how to read minds, then why are you reading?