Below is a lightly edited transcript. For the article that inspired this one, see Genetics is Nurture.
Welcome to the btrmt. Lectures. My name is Dr. Dorian Minors, and if there’s one thing I’ve learnt as a brain scientist, it’s that there’s no instruction manual for this device in our head. But there are patterns to the thing—patterns of thought, of feeling, of action. That’s what brains do. So let me teach you about them. One pattern, one podcast, and you see if it works for you.
So we’re officially past the introductory lectures and into the full swing of things. This is my shorter introduction—I’ll be curious what you think.
And now, to get things on the straight and narrow, I want to do a series of bits that I have on questions that seem important but don’t actually really end up mattering for most people. Certainly not in the way that they’re typically deployed. Typically, they’re deployed like stupid questions that make you seem smart.
And I’m going to tell you about one.
The Gender Essentialist Fantasy
I have an article called Genetics is Nurture. I say there:
There’s a constant tension in any animal science between the impact of nature and the impact of nurture. How much of who we are and what we do is the result of our genetic predispositions, and how much is because of our environment?
But this isn’t just a delicate sparring match between academics. Instagram and TikTok are chock-a-block with people claiming evolutionary motivations for stuff that have been corrupted by or are at odds with our socialisation. And the most common one, at least currently, is gender. People love Buss’ sexual selection stuff, even if they always get it wrong. The idea—to be a bit glib—is that men evolved to be powerful resource hunters and leaders of the household, and women evolved to be homemakers ready to breed at a moment’s notice. And the modern world has us all messed up because we’re trying to go against our evolutionary natures in this regard.
Even if you find this fantasy sexy—and I must admit that I do find this fantasy a bit sexy—you should still at least admit that it’s stupid. And I’ll give you three reasons why.
Evolutionary Stories Are Just Stories
Firstly, evolution, as an explanation, is completely overrated. This is something I write about again and again, and I’ll put some links to that in the show notes. But essentially, you can tell any story you like by appealing to evolution. They have this “it could be anything” quality about them. You know, like you might ask, why do giraffes have long necks? It could be because their ancestors had to find food higher on trees—the bed of food was just higher, so their necks grew longer. But equally, it could be that longer necks made them more deadly in the odd combat that giraffes get stuck into when they smash their necks against each other. And so on and so forth. You can come up with any kind of evolutionary story to explain any kind of thing.
And that’s not to say that evolutionary narratives don’t have a place. We should at least test our theories against an evolutionary perspective so that we don’t come up with a bunch of fantastic dead-end notions like Freud’s Oedipal desires and death instincts. These are things that just aren’t contiguous with what we know about evolutionary theory. But trying to do more than just test our theories against them is just story time. You have infinite explanations and nobody can go back in time to prove the counterfactual.
So that’s one reason: evolutionary stories are just stories.
Genetics Is Nurture
The second reason is that genetics just is nurture. They’re very difficult to distinguish.
Genetic evolution is the product of the environment at different time points. And this is actually true in two ways.
The first way is the most obvious one. Obviously genetic evolution is evolving in response to the environment, and it can happen surprisingly fast. We have evidence for it happening in thousands of years, if not hundreds of years. A community of people who spend so much of their time diving in the ocean that their lung capacity has changed within a thousand years.
And more surprisingly, although I must admit I’m pretty sceptical of epigenetics and post-genomics—it really does seem like it’s starting to become the new evolutionary theory with regard to explaining everything, and it’s also very notable that we saw a lot about epigenetics and then all of a sudden it went very quiet. That’s a red flag to me as well. But regardless, there is some tantalising evidence, and indeed the entire body of literature points to genetic changes that happen within one generation or even within our lifetime.
And for anybody who doesn’t know what epigenetics is, I’ll put a link in the show notes, but this is the idea that genetic changes can be passed down from parent to child. And there are some fantastic studies on anxiety in rats where genes related or associated with anxiety—when a rat is anxious and gives birth, that child has those same genes expressed. This is the kind of thing that epigenetics looks at. Within one generation.
And in my article, which I’m speaking to here, I also talk about the phenomenon of jumping genes. Now, jumping genes are these DNA sequences that can move their position, changing the form and the function of other genes. And we don’t really know exactly what they do, what their role in the body is, but there’s heaps of them. There’s this one particular sequence that might make up almost a sixth of the entire human genome. And what we think they probably do is relate to regulation of gene expression. So we know that bacteria use them to develop antibiotic resistance, which is not good for us, but it gives us a clue as to why they’re useful for us.
So epigenetics, post-genomics literature that’s pointing to genetic changes that happen within our lifetime—maybe, maybe not. But certainly in a generation, and if not hundreds or thousands of years, much faster than the millennia that people usually point at.
And if anything, it’s probably speeding up. There’s this concept called neutral evolution or genetic drift. And what it suggests is that most genetic developments really just aren’t substantial enough to be weeded out by natural selection. They’re these sort of random stochastic mutations that aren’t really that helpful. They’re not really that harmful. They don’t do anything for us, but they don’t hold us back.
And what’s really interesting is as we get better at keeping ourselves alive, essentially more of these mutations fall into this category of neutrality. All our health innovations mean that harms that once would have been quite harmful aren’t really that important any more. And this effect is biased in an interesting way. The bigger the mutation, the more likely it is to be weeded out by natural selection. But health innovation is targeted solely at mitigating the costs of these harmful mutations. We do a lot to keep people from getting sick—certainly more so in fact than keeping them from flourishing. And this is for obvious reasons. So reducing these sort of evolutionary penalties is going to increase the amount of genetic drift that evolution allows to propagate in the environment.
So genetic evolution happens pretty fast. And it is a product of the environment that we’re in. That’s what genetics does. It encodes the history of our being in the world.
The second way that genetics is a product of the environment is actually built into the way that scientists and geneticists talk about it. You’ll never hear a scientist talk about the “genetic-ness” of something when they’re trying to describe its genetic influences. What you’ll hear them talk about is this word called heritability.
Heritability is a statistic that tells us how much of the variation in some trait that we have at some time point, within some population, and under certain environmental conditions can be attributed to genetic differences. And all that qualification—I mean, it sounds complicated, but it’s necessary because you can’t study genetics in a vacuum. Genetics necessarily relies on the environment. Because if the environment changes, then the relative contribution of genetic variance can change, even if your biology is exactly the same.
I’ll give you an example. A good example of this is that the heritability of height increased all over the place in the 20th century. And this is probably—at least, people seem to think—not just because our nutritional environments became better, but actually because our nutritional environments became more uniform. So people are eating the same from culture to culture, and as a result you can see more differences in genetic expression. More genetic differences showed up.
And the point of this is to say that genes just don’t have intrinsic effects independent of the environment. Under these circumstances—people eating the same—these genetic differences are showing up. But under previous circumstances when people were eating differently, the genetic differences didn’t show. There’s no reason to privilege some historical genetic story because whatever genetic story you’re trying to tell might not apply now, or might not have applied then under these conditions or those, because the same genes can produce entirely different outcomes.
All of this to say: between just the fact of heritability and the fact that genetic evolution itself is encoding the environment into our bodies and the possible speeding up in the form of genetic drift—genetics is the same thing as nurture in important ways.
Why It Doesn’t Matter Anyway
And that leads us to my conclusion. And my conclusion is easy. It’s my third reason that nature versus nurture as a concept is a stupid question, which I think applies even if you don’t accept the other two.
And that’s that evolutionary stories are just boring. They’re true Malcolm Gladwell shit. And when I say that, I’m referring to this other article of mine where I talk about what Murray Davis called the sociology of the interesting. What Murray Davis noticed is that what makes an academic theory interesting is the ones that subvert our weakly held beliefs. They’re hot takes on things that we don’t care very much about. So if our strong beliefs are attacked, then we’re likely to resist the attack. But if our existing beliefs are confirmed, we’re likely to do very little but nod and forget. What we find really interesting is if the stuff we don’t care about very much is revised.
That’s what Malcolm Gladwell does in his books. The same, in fact, that I’m using for this podcast right now. And that’s what nature and nurture is often speaking to. They’re superficially sexy because they can revise any belief that you have. There are infinite evolutionary stories, but practically they’re completely useless.
No one has ever come to me with a convincing reason to believe that understanding something as being the product of nature rather than nurture meaningfully helps me. Not just because there could be any number of competing explanations, nor because I can’t disentangle them from the environment. If only it’s because it’s so obvious that the environment matters way more. And if things truly are immutable, then frankly, I’m not enough of a fatalist to want to believe it.
So, all that to say: nature and nurture. Why bother even asking?
