When I think of evolutionary psychology I generally jump to sharp and well defined claims that "mental modules" exist that (1) enable superior cognitive performance in specific domains relative to what typical people can do when they rely on "general reasoning" faculties, (2) evolved due to positive selection on our ancestors to deal with problems we faced over and over in our evolutionary history, and (3) should be pretty much universal among humans who don't have too many deleterious mutations.
When I think of people who focus specifically on innate human differences, I generally think of them studying much more abstract "traits" like performance on game theoretic tasks, or personality measures, or IQ. The sharp claims here mostly have to do with heritability numbers and whether a trait is "highly heritable" or "not very heritable".
Having this perception of two broad "kinds of research" my impression is that they do not seem to "play nicely" together. In some senses they don't address the same issues and in some senses they may have contradictory predictions.
First I'm curious as to whether you think different scientists really take generally different approaches in the way described here?
Assuming yes, do you think their research programs actually predict that people should see different things when examining "the same" phenomena?
Assuming yes, do you have a preference for one set of claims versus the other?
No matter where you step off of the train of questions, "Why or why not?" :-)
I think your perception is correct, but I am no expert. I sense that evolutionary psychologists are really interested in human universals: the famous experiments of Tooby and Cosmides go right to that point. Why are we all afraid of snakes? Why are our babies do hard to toilet train? But they generally don't have a lot to say about variation among humans in these traits.
The other sort that you and I both perceive are interested in human diversity and aren't much concerned with the bigger questions of the ev psych people.
No, they don't "play nice...
Edit: Q&A is now closed. Thanks to everyone for participating, and thanks very much to Harpending and Cochran for their responses.
In response to Kaj's review, Henry Harpending and Gregory Cochran, the authors of the The 10,000 Year Explosion, have agreed to a Q&A session with the Less Wrong community.
If you have any questions for either Harpending or Cochran, please reply to this post with a question addressed to one or both of them. Material for questions might be derived from their blog for the book which includes stories about hunting animals in Africa with an eye towards evolutionary implications (which rose to Jennifer's attention based on Steve Sailer's prior attention).
Please do not kibitz in this Q&A... instead go to the kibitzing area to talk about the Q&A session itself. Eventually, this post will be edited to note that the process has been closed, at which time there should be no new questions.