From the author:
“In the course of co-teaching a seminar on primate and human sexuality with my colleague Donald Symons he presented a proposed list of pan-cultural human sex differences. I bet him on the spot that I could find an ethnographically-described society in which all those traits were reversed. I lost that bet. At about the same time I noted a few studies published in a short period of time that each overthrew some classic anthropological account of a society that purportedly exhibited the opposite of what westerners might assume to be universal. All this led me to question the strong cultural-relativist position that I (and the majority of anthropologists) had largely taken for granted.
“I decided to look into the evidence and reasoning that might support more attention to human universals than they were then receiving. The result was this book and a few papers that expand on one or another facets of the matter.”