"And the religious right has been the chief force against teaching evolution."



Quoted from Barbara Forrest, a Southeastern Lousiana University philosophy professor and prominent critic of creationist science.)

It's a widespread view, but true in only a narrow sense. People who say they are against teaching the theory of evolution are very likely to be Christian fundamentalists. But people who are against taking seriously the implications of evolution, strongly enough to want to attack those who disagree, including those who teach those implications, are quite likely to be on the left.



Consider the most striking case, the question of whether there are differences between men and women with regard to the distribution of intellectual abilities or behavioral patterns. That no such differences exist, or if that if they exist they are insignificant, is a matter of faith for many on the left. The faith is so strongly held that when the president of Harvard, himself a prominent academic, merely raised the possibility that one reason why there were fewer women than men in certain fields might be such differences, he was ferociously attacked and eventually driven to resign.



Yet the claim that such differences must be insignificant is one that nobody who took the implications of evolution seriously could maintain. We are, after all, the product of selection for reproductive success. Males and females play quite different roles in reproduction. It would be a striking coincidence if the distribution of abilities and behavioral patterns that was optimal for one sex turned out to also be optimal for the other, rather like two entirely different math problems just happening to have the same answer.



The denial of male/female differences is the most striking example of left wing hostility to the implications of Darwinian evolution, but not the only one. The reasons to expect differences among racial groups as conventionally defined are weaker, since males of all races play the same role in reproduction, as do females of all races. But we know that members of such groups differ in the distribution of observable physical characteristics--that, after all, is the main way we recognize them. That is pretty strong evidence that their ancestors adapted to at least somewhat different environments.



There is no a priori reason to suppose that the optimal physical characteristics were different in those different environments but the optimal mental characteristics were the same. And yet, when differing outcomes by racial groups are observed, it is assumed without discussion that they must be entirely due to differential treatment by race. That might turn out to be true, but there is no good reason to expect it. Here again, anyone who argues the opposite is likely to find himself the target of ferocious attacks, mainly from people on the left.



Next consider the whole nature/nurture debate, in which the left has, for half a century or more, mostly taken a strong pro-nurture position. It is hard to see how humans could have evolved intelligence if intelligence is not heritable.



Finally, consider the question of how maleable human nature is or isn't. It is not logically impossible that we evolved as general purpose computers, with all details determined by the program, not the hardware. But it does not seem likely, given the obvious advantages of hardwiring in whatever rules worked in the environment where we evolved. Nor does it seem plausible given that most of our evolutionary history predates human rationality, making it likely that humans retain quite a lot of pre-human traits.



To be fair, one of the most important supporters of the evolutionary view in this particular context is also a prominent left wing intellectual: Noam Chomsky. His professional reputation, after all, was largely due to convincing arguments for the proposition that human linguistic abilities were to a large extent hardwired. I am sure he is not the only example; it is possible to defend conclusions, left, right, libertarian, or other in a variety of different ways. Not everyone on the left rejects the conclusions of evolution, any more than all Christians do.



Nonetheless, I think there is a pretty clear pattern. Almost everyone on the left believes that he believes in evolution. Yet I find it hard to think of any proposition popular on the left that is deduced from that belief. And, as I think I have shown, important dogmas of much of the left are inconsistent with it.



[An interesting discussion of evidence and theory on male/female differences is webbed here .]