I have a colleague in the psychology department, Brad Sagarin, and we have started gathering some data to explore other evolutionary hypotheses [for jealousy], like the one that I articulate in the book. [Editor's note: Called the relationship jeopardy hypothesis, it supposes that men and women have the same evolved capacity to learn to distinguish threats to the relationship from nonthreats.] We're still just gathering data. One thing that we're talking about in the research group is ways of creating jealousy in a laboratory setting. Coming up with a way of doing this that is ethical is not at all that easy. The easy way is to use the same sorts of questionnaire studies that have been used before, but to broaden the questions that you use them to address.

One piece of propaganda that people in the Evolutionary Psychology paradigm have used in support of their approach is [to assert] that throughout the history of psychology, evolutionary thinking has been almost entirely absent. They present themselves as having the courage to ask evolutionary questions about human psychology. Certainly we have evolved, like all other life on the planet, and we should be looking at human psychology from an evolutionary perspective. My disagreement with the Evolutionary Psychology paradigm is with respect to what follows from taking an evolutionary perspective on human behavior and psychology. The paradigm [supposes] that a lot of very specific doctrines immediately begin to follow once you take that perspective, and I don't think that's true. It's much more wide open.

JRM: What are other examples of proposed evolutionary explanations for human behavior that fall outside the paradigm?

DB: Some of the examples I discuss in the book are Barbara Smuts and David Gubernick's mating effort hypothesis concerning the evolution of marriage, and Kristen Hawkes's "grandmother hypothesis" for the evolution of menopause. In my opinion, these are terrific examples of work in evolutionary psychology, as opposed to Evolutionary Psychology. One significant difference between this work and the Evolutionary Psychology paradigm is that it isn't driven by an underlying "Grand Unified Theory" about the nature and evolution of the human mind. The good work to date, I think, has tended to be piecemeal, focused only on narrow aspects of human life history and decision-making.

The other major topic you address in the book is child abuse. You went so far as to collect data from the National Data Archive on Child Abuse and Neglect to examine patterns of abuse in the U.S. Why are you skeptical of the claim that parents are more likely to abuse stepchildren?

DB: It's a long and complicated argument. To oversimplify, I will say, first, we need to make sure that we're looking at the right sample. As I argued, to test evolutionary psychology's hypothesis, we need to look at physically abused children, not sexually abused children or children who were the victims of very broadly defined neglect. Second, in my study, the sample of physically abused children was 10 times the size of the sample in [a study by evolutionary psychologists Martin Daly and Margo Wilson]. Third, the differential I found in that larger U.S. study is readily accounted for by U.S. data regarding a diagnostic bias against those classified as stepparents. Fourth, I found clear evidence that much abuse in stepfamilies is at the hands of genetic parents. These things conspire to raise doubts about the "received view" of stepparental abuse.

JRM: Was your study peer-reviewed?

DB: A very brief version of it appears in an article of mine in the June issue of Trends in Cognitive Sciences. So some of it was published in a peer-reviewed journal a little after the release of my book. It wasn't rejected by peer-reviewed journals, either. I never submitted the research apart from my book.

JRM: Another recent book, The Case of the Female Orgasm, by biologist and philosopher of science Elisabeth Lloyd, examines the evidence for various adaptive explanations of female orgasms, and concludes that it has no evolutionary function. Do you think she's right?