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 Reference Bartholomew and Horowitz1991). 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 reproductive 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. Reference Tracy, Shaver, Albino, Cooper and Florsheim2003). 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 Reference Bogaert and Sadava2002). 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 Reference Brennan and Shaver1995; Schachner & Shaver Reference Schachner and Shaver2002), 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 Reference Bartholomew and Horowitz1991; Hazan & Shaver Reference Hazan and Shaver1987), 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 intimacy and closeness because, at least explicitly as part of an emotion-regulation strategy (Fraley & Shaver Reference Fraley and Shaver1997), 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. Reference Birnbaum, Reis, Mikulincer, Gillath and Orpaz2006), and consequently, is engaged in less frequently (e.g., Brassard et al. Reference Brassard, Shaver and Lussier2007). However, only dismissing-avoidance is associated with engaging in casual sex in lieu of intimate relationships (Schachner & Shaver Reference Schachner and Shaver2004).

Thus, Del Giudice's model does not apply to a significant proportion of avoidant individuals, namely, fearful-avoidants. Further, even if one distinguishes between the two avoidant patterns, 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 Reference Bogaert and Sadava2002), or that they engage in other short-term mating strategies, such as extra-paired sexual affairs (Bogaert & Sadava Reference Bogaert and Sadava2002; Gangestad & Thornhill Reference Gangestad and Thornhill1997). Thus, there is limited evidence supporting Del Giudice's claim that dismissing-avoidant men engage in short-term mating strategies.

As an alternative explanation, we propose that dismissing men who engage in casual sex do so to satisfy attachment-related needs, irrespective of direct reproductive outcomes. Research shows that avoidant individuals are more likely to cite external motivations for engaging in sex (“to fit in better,” “to be able to say you've done it”), which suggests that they engage in sex to seek social status and to avoid peer rejection (Schachner & Shaver Reference Schachner and Shaver2004). Consistent with the idea that attachment-related needs underlie engaging in sexual behaviors for avoidant individuals, greater frequency of casual sex appears to be independent of sex drive (Schachner & Shaver Reference Schachner and Shaver2002).

Moreover, we question whether a short-term strategy is more beneficial than a long-term strategy for dismissing individuals. We consider this from both a sexual strategies perspective, in which individuals aim to maximize their fitness, as well as an attachment perspective (Bowlby Reference Bowlby1982), according to which individuals aim to maintain close ties with others to promote feelings of security and well being.

From a sexual strategies perspective, pair bonding in humans increases fitness (Hazan & Diamond Reference Hazan and Diamond2000). It promotes parental investment in offspring, thereby increasing offspring survival. Further, it increases the chance of fertilization, given the covert ovulation cycle in women and that the frequency of women's ovulation cycles increases within pair bonds (Veith et al. Reference Veith, Buck, Getzlaf, Van Dalfsen and Slade1983). As a result, sex within a committed relationship is more likely to lead to reproductive success than promiscuous sex. Moreover, although individuals who engage in casual sex may have a greater number of partners per year, the frequency of engaging in sex is likely to still be higher for dismissing individuals within committed relationships. In short, it has not been established that a short-term mating strategy will increase fitness for dismissing men.

From an attachment perspective, the physical, psychological, and social benefits of mother–child bonds (Harlow & Harlow Reference Harlow, Harlow, Schrier, Harlow and Stollnitz1965) and pair bonds (Uchino et al. Reference Uchino, Cacioppo and Kiecolt-Glaser1996) are well-documented. The magnitude of attachment-related benefits on health and mortality are approximately the same as the detrimental effect of smoking on health (House et al. Reference House, Landis and Umberson1988). Moreover, the benefits of pair bonding and the costs associated with lack of a mate may be greater for men than women (Cramer & Neyedley Reference Cramer and Neyedley1998). Further, the nonrandom pairing of anxious women and avoidant men (Kirkpatrick & Davis Reference Kirkpatrick and Davis1994) may be extremely beneficial for dismissing-avoidant men. This pairing of dismissing men, who have low levels of caregiving, with anxious women, who are prone to compulsive caregiving, would enable dismissing men to benefit from pair bonding without the cost of having to provide care (Feeney & Collins Reference Feeney and Collins2001). Given these considerations, it is not surprising that a substantial proportion of dismissing-avoidant individuals still commit to relationship partners (Bogaert & Sadava Reference Bogaert and Sadava2002), instead of remaining unpaired (although less so than secure individuals).

In summary, we argue that Del Giudice's model ignores the majority of avoidant men, namely, fearful-avoidant men. Moreover, given the limited evidence that dismissing-avoidant men engage in short-term mating strategies, it may not even apply to the subset of men who are dismissing-avoidant. Finally, Del Giudice ignores the benefits of human pair bonding both on, and independent of, reproductive outcomes for dismissing men.