Well, not the only substantive issue, but possibly the main one raised by Rebecca Watson’s Skepticon 5 talk. Ed Clint’s post actually did a good job of concisely summarizing the issue, but it’s to paragraphs in a long post so let me pull them out:
Evolutionary psychologists only lean heavily on non-controversial facts about the past. For example, pregnancy involves numerous costs, and we therefore expect that females in many species will be more picky about mating than will males. This prediction has strong empirical support for both humans and other animals. Source
EP theories must make testable claims and do so. Example: Robert Trivers predicted that, among all animals including humans which have two sexes, the sex with the greater minimum investment in offspring should be more sexually choosey and the other more sexually aggressive/promiscuous. A comparative study of animal behavior could easily disprove his theory, though it has been confirmed by many observations.
Trivers’ original paper can be found here; a more recent paper with a good discussion of the issues and the results of a cross-cultural survey on desire for sexual variety can be found here. Note that the claim that women are more choosy about sexual partners than men are is not the claim that “women hate sex,” which Watson attributed to evolutionary psychologists in her talk. I, for one, am quite confident the first claim is true but equally confident that the second claim is false.
It would be interesting to hear Watson (and Stephanie Zvan, PZ Myers, and everyone else in the skeptic movement whose set themselves up as a critic of evolutionary psychology) explain what they think of the above paragraphs and papers. They certainly seem to make interesting claims, and since Watson claims that any good evo psych would be boring, it seems she’s committed to claiming none of that is good evo psych. But if that claim was merely misleading, this would be a good example to use clearing that up.
One thing that may be going on with some members of the anti-evo psych crowd is that they recognize that Trivers isn’t on par with Kanazawa–but they don’t think there’s much difference, so they don’t think there’s any need to be terribly careful distinguishing between the two. But if that’s what they think, they should say so.