Adaptations to Ovulation: Implications for Sexual and Social Behavior

Abstract

ABSTRACT—In sociallymonogamous species in whichmales heavily invest in offspring, there arises an inevitable ge-netic conflict between partners over whether investing males become biological fathers of their partners ’ off-spring. Humans are such a species. The ovulatory-shift hypothesis proposes that changes in women’s mate pref-erences and sexual interests across the cycle are footprints of this conflict. When fertile (mid-cycle), women find masculine bodily andbehavioral features particularly sexy and report increased attraction to men other than current partners. Men are more vigilant of partners when the latter are fertile, which may reflect evolved counteradap-tations. This adaptationist hypothesis has already gener-ated several fruitful research programs, but many questions remain. KEYWORDS—mating; evolutionary psychology; attraction Human sex can result in conception only about 20 % of the time: from 5 days before ovulation to the day of ovulation. Yet unlike in humans ’ close primate relatives, human females lack conspic-uous sexual swellings that vary across the cycle, and people have sex throughout the cycle. Continuous receptivity, however, need not imply that women’s sexual interests or preferences remain constant. Indeed, it would be surprising if selection had not forged psychological adaptations in one or both sexes to be sensitive to conception risk—and recent research confirms this expectation. The ways people are sensitive to it provide keys to understanding how selection shaped human sexual relations. In short, romantic relationships take shape out of people’s adaptive design for cooperating with partners—often lovingly—in pur-suit of shared interests, in conjunction with each sex’s adaptive design for pursuing its own interests (or those of same-sex an-cestors) that conflict with those of partners.