MATING AND MALE AGGRESSION 827 sion.which tend to be (wn en (e.g..ver bally Daly' (1985)portrait of the Yo ng Male Syndrome impli tha which ally hy n who lack terna this n mind re of direct sion g men from ages 18 to 30 years old (Eisner 2003 us e clatng var exan eth ons plac e la encroach upc mip (e.g.. er et al. 0091. ggressive behavior and d viduals who are al dy pair-bonded: ects were found for mates.Thus.although single versus partnered i dividuals migh The theory we tested in this bas on able that ffect the hich uld be ore strongly affect which mating goals i and violene ol men to unprovok gg s to increase (Gri 12).Historical r 1082 vide for effects tury China have als al unrest (Hudson 2 ha cts of ties for future. prof iolecntbechavio Conclusion This res earch offers th ng that proximatem s in 's lev avior a gr ody of researc nking nmo the rk of evolu ld h on we co les high lity that and the situation but underlying reproductiv e vior to th about when.why.and in whom viol nce is likely to occu 1990 Men low in tes References J.(2004).Sex ditfe .g..Li et al..2009).Futu motive in de 319-345.6101 mdobehoalReai8 200412007 minance over ol ,J.200 s040525x090951did not measure indirect or verbal aggression, which tend to be more common among women (Archer & Coyne, 2005). There may be cases in which mating motives would lead women to indirectly aggress against other women (e.g., verbally derogating a romantic rival; Buss & Dedden, 1990), and future studies would benefit from more fully testing the conditions under which mating-related concerns affect agonistic behavior among women (see Griskevi￾cius et al., 2009). Additionally, these studies relied on a laboratory measure of direct aggression among strangers. Our goal was to provide rigorous experimental tests of the link between mating motives and aggression, and the noise blast task provides an excellent behavioral measure of aggression. Nevertheless, ethical considerations place constraints on studying aggression in the lab, and future research would benefit from investigating other forms of aggressive behavior and doing so in other social contexts. The current findings provided somewhat inconsistent evidence regarding effects of mating motives on unprovoked versus pro￾voked aggression. Effects were found for unprovoked aggression in all three experiments, but provoked aggression only in Exper￾iment 3. The evolutionary theory we tested in this research does not provide a strong basis for differentiating between provoked and unprovoked aggression, and thus we had no a priori hypoth￾eses about which would be more strongly affected by the mating primes. Although there is evidence to suggest that provocation is likely to increase male violence, there is also evidence that both provoked and unprovoked aggression can play a role in male dominance competitions (Archer, 2004; Daly & Wilson, 1988; de Waal, 1982). We found stronger evidence for effects on unpro￾voked aggression than provoked aggression, and we suspect this is due to the fact that provocation, on its own, can elicit violent responses, and thus provocation may have obscured the effects of priming. Future research could profitably explore the extent to which the level and nature of provocation interacts with mating goals to affect violent behavior. There are likely to be several theoretically interesting moderat￾ing variables left unexplored by these studies. One potentially important variable is men’s level of testosterone. Testosterone is linked with the strength of men’s short-term mating motives (e.g., McIntyre et al., 2006) and with their propensity to use aggression as a means of attaining social dominance (Archer, Birring, & Wu, 1998; Mazur & Booth, 1998; see also Ronay & von Hippel, 2010). Indeed, the moderating effect of sociosexual orientation in this research is consistent with the possibility that effects of mating motives on aggression would be particularly pronounced among males high in testosterone—a possibility that has been observed in a variety of other species (e.g., Archer, 2006). Evidence for the challenge hypothesis, for example, implies that increases in ag￾gressive and competitive behavior during mating season are me￾diated by high levels of testosterone (Wingfield, Hegner, Dufty, & Ball, 1990). Men low in testosterone, who tend to be less physi￾cally imposing, may be more inclined to assert their dominance via less aggressive strategies (e.g., strategies that rely on humor or intelligence; e.g., Li et al., 2009). Future research would benefit from directly examining the role of testosterone—and other indi￾vidual differences that covary with the strength of short-term mating motives—in determining the strategies people use to assert their dominance over others. Future experiments would benefit from considering men’s age to test whether relatively younger men (who sometimes lack alternative routes to attaining status) respond to mating primes with more pronounced aggressive responses than older men (who often have attained status through other means). Indeed, Wilson & Daly’s (1985) portrait of the Young Male Syndrome implies that competitiveness, risk taking, and aggression reflect sexually se￾lected behaviors perpetrated especially by young men who lack alternative routes to gaining status. With this in mind, it may come as no surprise that the rate of violent crime and homicide is highest among men from ages 18 to 30 years old (Eisner, 2003). An additional moderating variable to be examined in future research is a person’s relationship status. Although partnered men (and women) might aggress against potential rivals who attempt to encroach upon their relationship (e.g., Maner et al., 2009), sexual motives might be less likely to increase aggression among indi￾viduals who are already pair-bonded; such individuals would have less to gain from behaving aggressively because they presumably are less inclined to compete with others over gaining access to new mates. Thus, although single versus partnered individuals might both behave aggressively, there are reasons to think that different motives underlie their aggressive behavior (i.e., relationship pro￾tection vs. mate-search). Another moderating variable that might affect the extent to which mating goals increase aggression and violence involves the local sex ratio—that is, the ratio of men to women. When men outnumber women, competition among men for access to mates tends to increase (Griskevicius et al., 2012). Historical records indicate that locales with a male-biased sex ratio, such as 19th century China, have also experienced higher levels of violence and social unrest (Hudson & Den Boer, 2002). Directly examining these and other potential moderators provides valuable possibili￾ties for future research. Conclusion This research offers the most rigorous experimental evidence to date demonstrating that proximate mating motives increase aggres￾sive behavior in men. In doing so, these studies also link male aggression to an underlying desire to achieve dominance. These findings add to a growing body of research linking proximate psychological and behavioral processes to their ancestral roots. Indeed, the current research integrated theories of motivation and social cognition within the metatheoretical framework of evolu￾tionary psychology. In generating and testing hypotheses about male aggression, we considered not only proximate features of the person and the situation but also the underlying reproductive functions that aggression is designed to serve. Tying aggressive behavior to theories of sexual selection provides critical informa￾tion about when, why, and in whom violence is likely to occur. References Archer, J. (2004). Sex differences in aggression in real-world settings: A meta-analytic review. Review of General Psychology, 8, 291–322. doi: 10.1037/1089-2680.8.4.291 Archer, J. (2006). Testosterone and human aggression: An evaluation of the challenge hypothesis. Neuroscience and Biobehavioral Reviews, 30, 319 –345. doi:10.1016/j.neubiorev.2004.12.007 Archer, J. (2009). Does sexual selection explain human sex difference in aggression? Behavioral and Brain Sciences, 32, 249 –266. doi:10.1017/ S0140525X09990951 MATING AND MALE AGGRESSION 827 This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly