Does evolution stop at the neck? Anyone who is skeptical about the details of popular forms of evolutionary psychology is liable to be charged with thinking so. Thus Ferris Jabr, commenting on my critique of the hubris of some of evolutionary psychology, writes that, “Every cell in our brains — every moment of our mental lives — is intimately connected to the entire history of life on this planet” — as if this were something that I, and other skeptics, must have failed to appreciate.
Well, aside from the hyperbole (“entire”?), I’m happy to agree with him about the cells in our brains and to affirm that evolution doesn’t stop at the neck. But let’s remember that particle physics doesn’t stop at the neck, either. So does this mean that psychologists ought to be paying a lot more attention to quarks and leptons? Presumably not. The point here is that, although psychology needs to be consistent with the facts of particle physics or of evolution, just how much any branch of science can reveal about our minds is always an open question, to be decided on a case by case basis. In the case of physics, the answer is probably not all that much. In the case of evolution, I believe it is rather more. But not as much, I suspect, as Jabr thinks.
He’s quite right, though, to pounce on my statement that “you don’t have to know about the evolution of an organ in order to understand it.” That carelessly invited misunderstanding. I should have spelled out what I meant: that it is not always necessary to know about the evolution of an organ in order to understand its basic function (as the example of William Harvey illustrates). I’m happy to affirm that evolutionary analyses can, of course, deepen our understanding of our organs. Since Jabr quotes me as writing that “if you did manage to trace how the brain was shaped by natural selection, you might shed some light on how the mind works,” it should be clear that we don’t disagree on matters of principle. He writes interestingly about changes in brain size over the course of human evolution. Perhaps such research will eventually shed important light on our mental lives. We’ll have to wait and see.
The most inflated and confused claims for evolutionary psychology, it seems to me, are the suggestions that policymakers need to pay much more attention to its findings. It is in this context, and this context alone, that I argue that, “It doesn’t make any practical difference exactly how our traits became established. All that matters is that they are there.” Jabr is mistaken in construing this as an injunction to scientists to abandon all research that does not have immediate practical applications. I’m sorry if that was not clear. If I were a biologist, I would be trying to delve into our evolutionary past. If I were a policymaker, I hope I’d focus on what we know about our present. As a critic, I’m trying to point out the difference.