Sex ratio and mate preferences: A cross-cultural investigation

Sex ratio is the number of men per 100 reproductive-age women within a specified mating pool. We generated and tested two hypotheses about the cross-cultural relationships between sex ratio and mate preferences using preference ratings of 18 characteristics provided by 9809 participants and corresponding sex ratio data secured from an international organization. The Classical Sex Ratio Mate Preference Shifts Hypothesis predicts that in imbalanced sex ratio societies, the more numerous sex will lower their standards, to facilitate acquisition of a partner of the less numerous sex. The Alternative Sex Ratio Mate Preference Shifts Hypothesis predicts that in lower sex ratio societies, men will lower their standards to secure more short-term matings, whereas women will raise their standards to avoid deception by men seeking short-term relationships. Results supported the Classical Sex Ratio Mate Preference Shifts Hypothesis for men, and the Alternative Sex Ratio Mate Preference Shifts Hypothesis for women. Discussion addresses limitations of the current research and highlights future directions for research on the relationships between sex ratio and mating psychology and behavior. Copyright # 2006 John Wiley & Sons, Ltd. Social exchange and evolutionary psychological models of relationship formation have highlighted economic processes operating on the ‘‘mating market.’’ According to these models, for example, individuals mate assortatively (Buss & Barnes, 1986; Cameron, Oskamp, & Sparks, 1977) and thereby acquire the best match for their own ‘‘mate value’’ (Kenrick, Groth, Trost, & Sadalla, 1993). In addition, social exchange and evolutionary models have argued that the availability of potential mates also might affect mating behavior (Baumeister & Vohs, 2004; Becker, 1976). The availability of potential mates is indexed by the sex ratio, the number of men per 100 reproductive-age women (with 15–49 years commonly used to define the age range of these groups of men and women; see Fossett & Kiecolt, 1991). When the sex ratio is imbalanced, intrasexual competition to acquire a mate of the less numerous sex theoretically should increase in intensity among members of the more numerous sex. This competition includes displaying attributes and qualities desired by the less frequent and therefore more selective sex (Pedersen, 1991). European Journal of Social Psychology Eur. J. Soc. Psychol. 37, 288–296 (2007) Published online 18 August 2006 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/ejsp.357 *Correspondence to: Emily A. Stone, Department of Psychology, Florida Atlantic University, 2912 College Avenue, Davie, Florida 33314. E-mail: [email protected] Copyright # 2006 John Wiley & Sons, Ltd. Received 3 September 2005 Accepted 7 March 2006 Men’s behavior and women’s behavior reflects these predicted shifts in competition. For example, men are more interested than women in casual sex (Buss & Schmitt, 1993; Clark & Hatfield, 1989). Correspondingly, lower sex ratio societies—in which women more than men compete for mates—are characterized by higher rates of self-reported female promiscuity (Schmitt, 2005), women’s shorter skirts (Barber, 1999), and higher rates of illegitimate births (South & Trent, 1988) and teenage pregnancies (Barber, 2001). In contrast, higher sex ratio societies—in which men more than women compete for mates—are characterized by behaviors consistent with psychological sex differences produced by sex differences in minimum obligatory parental investment (i.e., men’s minimum investment of a small amount of time and sperm, relative to women’s minimum investment of 9 months of gestation and years of lactation; see Trivers, 1972). Most notable of these resultant psychological sex differences includes women’s greater interest in cues of commitment (Buss, 2003). As such, higher sex ratio societies have lower divorce rates, more stable marriages (Pedersen, 1991; Secord, 1983), and earlier age of first marriage (South & Trent, 1988). Lichter, Anderson, and Hayward (1995) found that, consistent with women’s greater interest than men’s in a potential mate’s status and resources (Buss, 1989; Feingold, 1992), women in higher sex ratio societies are more likely than women in lower sex ratio societies to actualize their preferences and marry a high-status man rather than a low-status man. Previous research indicates that there are shifts in mating behavior according to the sex ratio. As Jennions and Petrie (1997) note, however, there are two aspects of mating preferences: preference functions (or preferences for characteristics that drive mate selection—the focus of this article), and choosiness (pertaining to actual mate selection). Constraints on mating options, such as an imbalanced sex ratio, are associated with shifts in behavior produced by heightened intrasexual competition among the more numerous sex to display characteristics desired by the less numerous sex. Are these behavioral shifts accompanied by psychological shifts in mating preferences? In the current research, we generated and tested two hypotheses derived from Sex Ratio Theory (Guttentag & Secord, 1983). CLASSICAL SEX RATIO MATE PREFERENCE SHIFTS HYPOTHESIS As the supply of one sex decreases, so should the value of acquiring as a mate a member of that sex increase (Baumeister & Vohs, 2004). Just as men and women in imbalanced sex ratio societies shift mating strategies to embody the desires and preferences of the less frequent sex, might they also lower their standards, in an additional effort to acquire a mate? We hypothesize that in conjunction with increased effort to display qualities desired by the less numerous sex, men and women may lower their mate preference standards when they are members of the more numerous sex. The Classical Sex Ratio Mate Preference Shifts Hypothesis Across cultures, mate preferences will vary according to the availability of the opposite sex, such that each sex will decrease their preference ratings (i.e., report less stringent and limiting preferences) when they are members of the more frequent sex.