When I posted a few days ago about new books on the reading list, I said I’d have more to say about evolutionary psychology. So here’s an interview with one of the authors of Why Beautiful People Have More Daughters, a new book on evolutionary psychology by Alan S. Miller, Satoshi Kanazawa, and Stephen Hoye. I’m sure the book is entertaining and thought-provoking, but I have some doubts about its content nonetheless.
The basic idea is that our brain evolved in a different environment than the one we live in now, and that long-vanished environment has left its traces in our behavior, which is often at odds with the world we really live in. Evolutionary psychology (EP) aims to figure out the ways our current behavior has been shaped by the pressure of selection in the past. EP can offer some fascinating analyses of how we got to be the way we are, and why we do things that don’t necessarily make sense now (the reason is often that those things used to make sense).
However, it’s worth noting that another recent book about EP, Evolutionary Psychology as Maladapted Psychology by Robert C. Richardson, analyzes the explanatory power of EP and concludes that on the whole, EP doesn’t provide the kind of evidence that would be expected of arguments in other areas of evolutionary biology. I’m deeply interested in understanding how our brains and our behavior evolved, and I’m as intrigued as anyone by the kind of explanations evolutionary psychologists come up with, but a lot of the time I have to wonder how on earth they can prove their claims.
I haven’t read the Beautiful People book, but from what Satoshi Kanazawa says in this interview, it sounds like it may place a bit too much emphasis on the ways we’re “prisoner[s] to our hard-wiring”, as the interviewer puts it. This appears most glaringly to me in the two unanswered questions in EP that Kanazawa mentions at the end of the interview: Why do middle-class people in developed nations who have the resources to feed and raise larger families so often limit themselves to only two children? And why do people from big families not have small families themselves (since they have more siblings to share the load of passing genes along) and why do people from small families, or only children, have many children themselves (since they must make sure to get their parents’ genes into the next generation)?
Maybe there’s something I’m missing, but these questions seem to totally ignore cultural evolution, which is another strong force that influences our behavior. We’re more than just machines for passing along genes, and we are well able to control our behavior so that we act in the best interests of something other than blind reproduction. (In fact, some people consider that one of the most promising things about us.) Culture is of course constrained by our evolved capacities and limitations, but it does have a hand in shaping our behavior.
Another thing that bugged me about this interview is Kanazawa’s explanation of the history of evolutionary psychology. It’s not just that in 1992 a group of people decided to apply evolutionary ideas to human behavior; the roots of the field go back further than that (perhaps to E.O. Wilson’s book Sociobiology—maybe sociobiology and EP are not really the same thing, but they’re certainly closely related—or to Richard Dawkins’s The Selfish Gene). I know, this is just a short interview and we can’t expect a whole lot of detail or nuance, and maybe the book is more carefully written and rigorous than the interview would lead one to expect. But I have to admit that I’m not optimistic.
Hm. In addition to discounting non-genetic inherited characters (e.g., culture), some of this is just sloppy reasoning.
“Why do middle-class people in developed nations who have the resources to feed and raise larger families so often limit themselves to only two children?”
This becomes a conundrum from the standpoint of purely genetic evolution if we know that having more children would be in the long-term genetic interests of these middle-class parents. But–we don’t know that.
Humans are already on the far end of a continuum from many offspring with little investment per offspring to few offspring with heavy investment per offspring. If there weren’t tradeoffs that make having fewer offspring advantageous, we’d be breeding like guppies. Understanding these kinds of tradeoffs is an important field in evolutionary biology, but by no means are they unexpected or unique in humans.
“And why do people from big families not have small families themselves (since they have more siblings to share the load of passing genes along)”
If family size is heritable and thus subject to evolution (by any means, whether cultural or genetic), of course it must persist across generations. So this contains an odd self-contradiction; it amounts to asking: “Why is this heritable?” and expecting an evolutionary answer that presupposes heritability.
Patrick