Social exchange and evolutionary models of mate selection incorporate economic assumptions but have not considered a key distinction between necessities and luxuries. This distinction can clarify an apparent paradox: Status and attractiveness, though emphasized by many researchers, are not typically rated highly by research participants. Three studies supported the hypothesis that women and men first ensure sufficient levels of necessities in potential mates before considering many other characteristics rated as more important in prior surveys. In Studies 1 and 2, participants designed ideal long-term mates, purchasing various characteristics with 3 different budgets. Study 3 used a mate-screening paradigm and showed that people inquire 1st about hypothesized necessities. Physical attractiveness was a necessity to men, status and resources were necessities to women, and kindness and intelligence were necessities to both.

Sexual arousal is category-specific in men; heterosexual men are more aroused by female than by male sexual stimuli, whereas homosexual men show the opposite pattern. There is reason to believe that female sexual arousal is organized differently. We assessed genital and subjective sexual arousal to male and female sexual stimuli in women, men, and postoperative male-to-female transsexuals. In contrast to men, women showed little category specificity on either the genital or the subjective measure. Both heterosexual and homosexual women experienced strong genital arousal to both male and female sexual stimuli. Transsexuals showed a category-specific pattern, demonstrating that category specificity can be detected in the neovagina using a photoplethysmographic measure of female genital sexual arousal. In a second study, we showed that our results for females are unlikely to be explained by ascertainment biases. These findings suggest that sexual arousal patterns play fundamentally different roles in male and female sexuality.

We thank Jeff Berman and Robert Nicholson for their statistical advice and Sheri Berenbaum and Ray Blanchard for their comments.

SummaryOngoing political controversies around the world exemplify a long-standing and widespread preoccupation with the acceptability of homosexuality. Nonheterosexual people have seen dramatic surges both in their rights and in positive public opinion in many Western countries. In contrast, in much of Africa, the Middle East, the Caribbean, Oceania, and parts of Asia, homosexual behavior remains illegal and severely punishable, with some countries retaining the death penalty for it. Political controversies about sexual orientation have often overlapped with scientific controversies. That is, participants on both sides of the sociopolitical debates have tended to believe that scientific findings-and scientific truths-about sexual orientation matter a great deal in making political decisions. The most contentious scientific issues have concerned the causes of sexual orientation-that is, why are some people heterosexual, others bisexual, and others homosexual? The actual relevance of these issues to social, political, and ethical decisions is often poorly justified, however.

Sexual selection theory provides a powerful model for the analysis of psychological sex differences. This research examined (a) tests of several sex differences in mating psychology predicted from sexual selection theory, (b) broad developmental hypotheses about sex differences in mating psychology--through the relationship of mating psychology to sexual orientation, and (c) the structure of within-sex differences in mating psychology. Scales measuring aspects of mating psychology were administered to heterosexual and homosexual Ss of both sexes. The structure of scale intercorrelations was similar across groups. All scales yielded sex differences consistent with sexual selection theory. Homosexual Ss generally obtained scores similar to those of same-sex heterosexual Ss, though several scales were significantly related to sexual orientation. Findings constrain hypotheses concerning the origins of sex differences.