Catherine Page Harden

that are correlated with being more likely to engage in not just one form of externalizing, but all of them.

So these are genes that make it more likely for you to smoke and also to drink and also to have sex with more people and also potentially to aggress against another person.

And for some people listening, you might think, well, having sex with lots of people and aggressing against someone, those are totally different behaviors.

One is not necessarily harmful in any way.

And that's absolutely true.

But what all of these behaviors have in common is that at least someone in society says you shouldn't do them and you do them anyway.

And so what we see is that there's genes that are in common across all of these things.

Yeah.

So there's this idea that we can kind of pre-intuit or pre-know which behaviors are going to be influenced by genes and which aren't.

But then if we look in our history, we can see obvious examples where we were wrong in the past and our intuitions have shifted in response to science.

So schizophrenia used to be thought to be the result of a

schizophrenic mother, and we now know that it is very strongly heritable.

We used to think of obesity in terms of sloth and gluttony, and now, especially in the age of Ozempic, we can see that it's profoundly biological and can be manipulated by injecting a peptide in your body.

So we can see over time that societies always kind of have a carve out where we think, well, this behavior is somehow floating free of our body.

But that's almost never the case.

All of our behavior is being produced by a body, by a brain, and that brain is going to be shaped by the genes we happen to inherit.

So ordinarily, for the vast majority of people and for the vast majority of genetic variants, a difference between us and our genes makes only the tiniest bit of difference to our probability of

of showing a behavior.

I think the best analogy for helping people understand this is to think about height.

So there's a few people who inherit genes for gigantism that make them very tall or genes for dwarfism that make them very short.