Oh, and I see he’s speculating about my sex life. Real charmer, this guy.
In his non-response response, Brinkman doubles down on his fixation with the fact that, across human populations, males become more likely to be involved in violent crime right around the time we hit puberty:
Another reason I think meanness is partially genetic is the work of evolutionary psychologists Martin Daly and Margo Wilson, which interprets violent crime and murder as adaptive responses to high stress, competitive, dangerous environments. Daly and Wilson’s research is too complex to fully summarize here, but if you’re interested, their argument is captured nicely by this article …
… If the forms of meanness [documented by Daly and Wilson] aren’t at least partially caused by evolutionary adaptations, then why are they so much more likely to be perpetrated by young men than young women, starting at exactly the age of puberty, escalating until the average age of parenthood, and then declining until death? How could “culture” possibly explain that pattern completely, when the same trend can be found cross-culturally around the world? [Hyperlinks sic.]
Since it’s a point of contention that I’ve come across before in discussions of human evolution by non-biologists, let me go into a little more detail about why this pattern isn’t even “suggestive” that we could select meanness out of human populations. The problem, ironically, is the very universality of the pattern that Brinkman finds so compelling.
Consider another trait that is invariant across human populations: almost everyone on the planet has five fingers on each hand. Five-fingered hands absolutely have a genetic basis—they’re ultimately the product of the interaction of the regulatory and protein-coding genes that shape our development. But knowing this doesn’t tell us, when we see a man with only four fingers, that there’s a genetic basis to the variation he represents. Environmental conditions can have profound effects on human skeletal morphology, as the thalidomide tragedy illustrates pretty graphically. To test whether genetic variation is responsible for variation in finger number, we’d need to study lots of people with different numbers of fingers, raised in environments that are as similar as possible—not a dataset that shows how common it is to have five fingers.
In the same way, it may well be that there is something programmed into the development of human males that makes us, as a group, more likely to be violent once we’ve reached maturity—and, certainly, the development of boys into men is controlled by our genes. But natural selection (or artificial selection promoted by a nerd-rapper) needs genetic variation in order to operate. The fact that every male becomes more violent after puberty doesn’t tell us anything at all about whether individual differences in the magnitude of that change—differences that can be dramatic, both across and within cultural groups—are due to individual genetic differences. And if you don’t know that, you really can’t claim that you could select for reduced masculine meanness.
This is a somewhat subtle point, but it’s one that most evolutionary biologists would consider pretty basic to understanding how natural selection works. And, personally, I think it’s a point that anyone who wants to educate the public about evolution ought to be able to grasp.