Strategic pluralism suggests that women engage in short-term sexual relationships when the benefits to doing so outweigh the costs. We investigated attraction to indicators of good genes (namely, masculinity as demonstrated by point-light walkers) in women varying in menstrual cycle status and sociosexual orientation. When women are fertile, they have the ability to gain genetic benefits from a male partner and should also be attracted to high levels of masculinity in men as a signal of genetic benefits. Sociosexual orientation is an individual difference that indicates openness to short-term mating and, thus, should influence aspects of mating strategy. Women with an unrestricted sociosexual orientation, as compared to women with a restricted sociosexual orientation, are more likely to engage in short-term relationships and obtain fewer nongenetic resources from their mates. Thus, they should place heavy emphasis on male masculinity as a sign of genetic benefits available from their mates. In this study, women indicated the walker most attractive to them on a constructed continuum of male and female point-light walkers. In Study 1, fertile women, as compared to nonfertile women, showed a greater attraction to masculinity. In Study 2, women demonstrated a strong positive relationship between sociosexuality and attraction to masculinity.
Strategic pluralism suggests that women should generally engage in long-term mating strategies. However, if the benefits (e.g., genetic benefits for offspring) outweigh the costs of short-term mating (e.g., less parental investment, partner loss, unwanted pregnancy, etc.), then women should take advantage of short-term mating opportunities (Gangestad & Simpson, 2000). Evidence for strategic pluralism comes from women's preferences across the menstrual cycle. Because masculinity in faces (Penton-Voak & Chen, 2004), voices, body shape, and social displays (see Zitzmann & Nieschlag, 2001, for a review of the previous three factors) is associated with high testosterone levels and testosterone is an immunosuppressant, highly masculine healthy males are likely to be particularly immunocompetent (Folstad & Karter, 1992). Immunocompetency is a heritable genetic benefit available to a woman's offspring; thus, women engaging in short-term relationships should prefer highly masculine mates. Research has demonstrated that fertile women, as compared to nonfertile women, prefer higher levels of masculinity in faces (Johnston et al., 2001, Penton-Voak & Perrett, 2000 and Penton-Voak et al., 1999) and voices (Feinberg et al., 2006), as well as dominant male social displays (Gangestad, Simpson, Cousins, Garver-Apgar, & Niels Christensen, 2004).
Further evidence of strategic pluralism in human mating is demonstrated through research investigating the interindividual difference of sociosexual orientation. Sociosexual orientation represents a person's openness to short-term mating. People with relatively unrestricted sociosexual orientation, indicated by high scores on the Sociosexual Orientation Inventory (SOI; Simpson & Gangestad, 1991), are more likely to engage in short-term relationships than people with a restricted sociosexual orientation. Generally employing a short-term mating strategy, as compared to a long-term mating strategy, yields fewer nongenetic resources (i.e., parental effort) and increases the importance of receiving genetic benefits from sexual partners (Gangestad & Simpson, 2000). Thus, similar to women at times of peak fertility, women with unrestricted sociosexuality should prefer high levels of masculinity. Work by Provost, Kormos, Kosokowski, and Quinsey (2006) has demonstrated that unrestricted sociosexuality is related to greater attraction to the masculine mesomorph body type, as compared to average, endomorph, or ectomorph body types, and attraction to a male confederate for short-term relationships in a mock speed dating paradigm. Similarly, Waynforth, Delwadia, and Camm (2005) demonstrated that unrestricted sociosexuality in women was associated with attraction to male and female faces with masculine features.
Although there is evidence that both menstrual cycle status and sociosexuality are related to preference for masculinity, this research has only used static images and comparative judgments among stimuli that may have been confounded by variations in such characteristics as age, skin color, and health. These variables themselves influence interpersonal attraction (see, e.g.,Kenrick & Keefe, 1992, for age; Fink, Grammer, & Thornhill, 2001, for skin color; Buss et al., 1990, for health; and Jones, Little, Burt, & Perrett, 2004, for healthy skin in particular). In this study, we investigated the effect of menstrual cycle stage and sociosexuality on female attraction to masculinity using point-light displays of human walkers. Point-light displays limit the influence of confounding variables and, thus, are beneficial in testing specifically for a preference for masculinity. These stimuli contain information on walker structure and walking dynamics, both of which are key components in sex discrimination. For example, in addition to the hormonally influenced structural differences between men and women (e.g., broader shoulders and narrower hips in men compared to women), male walkers, as compared to female walkers, have a larger upper-body lateral sway (Mather & Murdoch, 1994), whereas women have a hip rotation that is in the opposite phase to vertical leg motion (Troje, 2003), resulting in more pronounced hip movement. Using point-light displays of biological motion, we investigated the unique effect of masculinity on attractiveness with fewer confounding variables. The first study investigated women's attraction to masculinity as a function of their female fertility, and the second study investigated women's attraction to masculinity as a function of their sociosexuality.
