forward, and ones that are consistent with the data reviewed by Del Giudice. The major challenge now is to develop and test a range of more critical empirical predictions. We propose one particular set of predictions for future research. The hypothesized link between attachment and adaptive variation in reproductive strategies (e.g., mating vs. parenting effort) implies that sexual relationships should be a key area for study. Much evi- dence suggests that women’s sexual strategies correlate with mate preferences on certain dimensions of physical attractiveness, such as male facial and vocal masculinity (Gangestad & Simpson 2000; Gangestad & Thornhill 2008; Provost et al. 2008). In combination with the arguments of the target article, this leads to the prediction that attachment styles should correlate with females’ preference for masculine faces and voices. In populations characterized by low paternal investment and high levels of aggressive male–male competition, there is a significantly stronger average preference among females for masculinized facial features than in populations characterized by higher paternal investment (Penton-Voak et al. 2004). The evolutionary logic is that, where there is low paternal investment, women’s mate choices should be more strongly biased towards males of high competitive ability. Similarly, women seeking short-term sexual relationships have a stronger preference for masculine features than those seeking long-term relationships (Little et al. 2002), again indicating a link between likelihood of paternal investment and preference for masculinity. The theoretical link to attachment processes is that female dismissiveness should cor- relate positively with masculinity preferences. On the other side of the coin, males with more masculine faces tend to have more sexual partners and be less interested in long-term relationships (Boothroyd et al. 2008). Consequently, facial masculinity should cor- relate with attachment profiles in males. Sexual strategies also vary according to the individual’s percep- tion of their own “market value” (Little & Mannion 2006). An intriguing corollary of the target article is that these perceptions may correlate not only with physical attractiveness, but also with the experience of attachment relationships in middle childhood. This would predict an association between attachment profile and self-rated attractiveness. Finally, female sexual strategies have been shown to be hormon- ally influenced. During the menstrual cycle, women become more interested in short-term relationships, are more likely to be unfaithful to their long-term partner, and are more attracted to masculine facial and vocal features around the time of ovulation, when the risk of conception is high (Penton-Voak et al. 1999; Fein- berg et al. 2006; Gangestad & Thornhill 2008). This has been inter- preted as reflecting a “dual” sexual strategy, promoting mating with competitive but low-investing males while also garnering paternal investment via a long-term relationship. A further prediction is therefore that attachment profiles should vary cyclically, directly mirroring the cyclicity in sexual behaviour. This would imply that attachment profiles, albeit perhaps largely fixed early in life, also have some previously unsuspected adaptive plasticity. What love has to do with it: An attachment perspective on pair bonding and sexual behavior doi:10.1017/S0140525X09000260 Vivian Zayas a and Daphna Ram b a Department of Psychology, Cornell University, Ithaca, NY 14853-7601; b Department of Human Development, Cornell University, Ithaca, NY 14853-7601. vz29@cornell.edu dr239@cornell.edu http://people.psych.cornell.edu/~pac_lab/ Abstract: Del Giudice proposes that short-term mating strategies are adaptive for attachment-avoidant men. We argue that this model (1) does not apply to the majority of avoidant men (fearful-avoidants); (2) is based on limited evidence that the remaining subset of avoidant men (dismissing-avoidants) engage in short-term mating strategies; and (3) disregards the importance of pair bonding even for dismissing- avoidants. A central assumption of Del Giudice’s model is that insecurely attached male infants develop an avoidant attachment strategy in adulthood that is associated with short-term mating strategies that maximize fitness. In this commentary, we first argue that Del Giudice’s model ignores the majority of men who engage in avoidant attachment strategies, namely, fearful-avoidant men, who constitute approximately 21% of the population (Bartholomew & Horowitz 1991). Moreover, the model does not accurately apply to dismissing-avoidant men, who make up approximately 18% of the population. Second, we question Del Giudice’s claim that the “link between avoidance and short-term mating style is well supported by research in adult attachment” (sect. 5.2, para. 3), as well as the idea that short- term strategies increase fitness for dismissing-avoidant men. Finally, we discuss a point overlooked by Del Giudice: the benefits of pair bonding on, and in the absence of, direct repro- ductive outcomes. Del Giudice claims that an avoidant attachment strategy is related to short-term mating strategies (e.g., an earlier onset of first sexual experience and higher frequency of sexual activity with different partners). However, empirical work does not unequivocally support this claim. There is evidence that avoidant male adolescents are less likely to ever have had sex, to have engaged in fewer sexual behaviors before trying intercourse, and to have sex less frequently (Tracy et al. 2003). In a sample of 327 adult men between the ages of 19 and 35 years, attachment avoidance was unrelated to frequency of sexual intercourse (Bogaert & Sadava 2002). Even though there is some evidence that attachment avoidance is associated with a higher frequency of casual sex (i.e., sex in the absence of a committed relationship) (Brennan & Shaver 1995; Schachner & Shaver 2002), this is only true for a subset of avoidant males. One explanation for this discrepancy is a distinction that Del Giudice relatively ignores: the difference between dismissing- avoidance and fearful-avoidance. According to adult attachment theory (Bartholomew & Horowitz 1991; Hazan & Shaver 1987), both dismissing-avoidant and fearful-avoidant people are uncomfortable with closeness and intimacy and avoid relying on attachment figures. A critical distinction between the two is in their level of attachment anxiety (i.e., concerns about rejection and abandonment by partners). Dismissing individuals avoid inti- macy and closeness because, at least explicitly as part of an emotion-regulation strategy (Fraley & Shaver 1997), they devalue the importance of close others and emotional ties. In contrast, fearful individuals avoid intimacy and closeness because they strongly fear being rejected. Thus, dismissing- avoidance is characterized by high avoidance and low anxiety, whereas fearful-avoidance is characterized by high avoidance and high anxiety. With respect to sexual behaviors, these two avoidant patterns share some similarities but also differ in important ways. Because both are uncomfortable with closeness, sexual activity is less satisfying, less pleasurable, and even aversive (Birnbaum et al. 2006), and consequently, is engaged in less frequently (e.g., Brassard et al. 2007). However, only dismissing-avoidance is associated with engaging in casual sex in lieu of intimate relationships (Schachner & Shaver 2004). Thus, Del Giudice’s model does not apply to a significant pro- portion of avoidant individuals, namely, fearful-avoidants. Further, even if one distinguishes between the two avoidant pat- terns, as proposed by attachment theory, Del Giudice’s model may still not be correct with respect to the short-term mating strategies of dismissing-avoidants. Although they engage in casual sex, there is no clear evidence that dismissing-avoidants have an earlier onset of sexual activity (Bogaert & Sadava Commentary/Del Giudice: Sex, attachment, and the development of reproductive strategies 44 BEHAVIORAL AND BRAIN SCIENCES (2009) 32:1