Vo loy o品8r Sex Begets Violence:Mating Motives,Social Dominance,and Physical Aggression in Men There are sizable gender and male s expen to del ful blasts of white (bu ctition with their d thu These findin nsigpold Why do giraffes have long the giraffe's long neck was r duced th ation to help with male du To a long neck etween mating-relat and chavior in mer od f ing.It is also sed on men's ge and have Male their ne d pns Da 1985 data and correl s (e.g eapons to establish dominance over other r males.Male xperimenta Human males do not ong necks like giraffes,but they do figh chain connecting mating motives to aggressive behavior.Thes and hist s Wilson,1988). Sexual Selection and Male Violence in par Sehmin.1993 Theories of sexual selection (Darwin.1871)and differentia Daly&Wilson.1983:Kenrick&Sheets,1993). within a given pecies,the sex with lower levels of minimum ldpcmororaccss s publish dae23.2012 ing aggres els o and Helen Rodrigues fo hceto-fhcecontir 1
Sex Begets Violence: Mating Motives, Social Dominance, and Physical Aggression in Men Sarah E. Ainsworth and Jon K. Maner Florida State University There are sizable gender differences in aggressive behavior, with men displaying a much higher propensity for violence than women. Evolutionary theories suggest that men’s more violent nature derives in part from their historically greater need to compete over access to potential mates. The current research investigates this link between mating and male violence and provides rigorous experimental evidence that mating motives cause men to behave violently toward other men. In these studies, men and women were primed with a mating motive and then performed a noise-blast aggression task. Being primed with mating led men, but not women, to deliver more painful blasts of white noise to a same-sex partner (but not an opposite-sex partner). This effect was particularly pronounced among men with an unrestricted sociosexual orientation, for whom competition over access to new mates is an especially relevant concern. Findings also suggest that mating-induced male violence is motivated by a desire to assert one’s dominance over other men: when men were given feedback that they had won a competition with their partner (and thus had achieved dominance through nonaggressive means), the effect of the mating prime on aggression was eliminated. These findings provide insight into the motivational roots of male aggression and illustrate the value of testing theories from evolutionary biology with rigorous experimental methods. Keywords: aggression, mating, motivation, evolutionary psychology Why do giraffes have long necks? Historically, scientists thought the giraffe’s long neck was produced through evolution to help with foraging—a long neck helps the giraffe reach food high in the treetops (du Toit, 1990). As it turns out, this is only part of the story, because the giraffe’s long neck is good for more than foraging. It is also good for fighting with other giraffes. Male giraffes often use their necks to engage in the (aptly named) behavior of necking—they use their necks as weapons to establish dominance over other males. Males who win these contests tend to enjoy greater access to female giraffes during mating (Simmons & Scheepers, 1996). Human males do not have long necks like giraffes, but they do fight with one another in many other ways. Indeed, across virtually all cultures and historical time periods, men have displayed a propensity for behaving violently toward other men, and this propensity is far more pronounced than any such behavior in women (Archer, 2004; Daly & Wilson, 1988). Evolutionary theories suggest that this gender difference can be explained, at least in part, by differences between men’s and women’s reproductive strategies (Buss & Schmitt, 1993; Daly & Wilson, 1983; Kenrick & Sheets, 1993). Although evolutionary theories provide a compelling view of male aggression, few experimental studies have tested the link between mating-related motives and violent behavior in men. Previous evolutionarily inspired studies of male violence have focused on men’s general propensity for aggressiveness and have relied primarily on archival data and correlational methods (e.g., Wilson & Daly, 1985). The current research provides rigorous experimental tests of the hypothesis that proximate mating motives cause men to behave aggressively. Moreover, the current research directly examines the role of social dominance—a key link in the chain connecting mating motives to aggressive behavior. These studies test a theory from evolutionary psychology that has yet to undergo rigorous experimental verification. Sexual Selection and Male Violence Theories of sexual selection (Darwin, 1871) and differential parental investment (Trivers, 1972) provide a basis for understanding an array of sex-differentiated behaviors. These theories suggest that, within a given species, the sex with lower levels of minimum obligatory parental investment must compete more for access to mates. Consequently, that sex will display higher levels of intrasexual competition and will experience greater pressure to display behaviors (including aggression) aimed at successfully procuring a mate.1 In humans, men have lower minimum obligatory levels of parental investment than women who, unlike men, experience 1 Theories of aggression differentiate between direct aggression (e.g., face-to-face confrontation) and indirect aggression (e.g., speaking badly about someone behind his or her back). The current research focuses specifically on direct aggression. This article was published Online First July 23, 2012. Sarah E. Ainsworth and Jon K. Maner, Department of Psychology, Florida State University. This research was supported by National Science Foundation Grant 1122785 awarded to the second author. We are grateful to Ashlee Black, Andrea Garcia, Irene Hernandez, Stephanie Holmes, Alanna O’Brien, Alexa Ralicki, and Helen Rodrigues for their assistance in conducting this research. Correspondence concerning this article should be addressed to Sarah E. Ainsworth or Jon K. Maner, Department of Psychology, Florida State University, Tallahassee, FL 32306-4301. E-mail: ainsworth@psy.fsu.edu or maner@psy.fsu.edu Journal of Personality and Social Psychology © 2012 American Psychological Association 2012, Vol. 103, No. 5, 819 – 829 0022-3514/12/$12.00 DOI: 10.1037/a0029428 819 This document is copyrighted by the American Psychological Association or one of its allied publishers. 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820 AINSWORTH AND MANER and childbirth.Women'srively higher level of signed not ony to help males self-present:it serves as a means ng th al sex ratio.which re nts th who is watchine Thus our research examines mating-induced eproductive cap of men mot dominance unerlies mting-induced male on See their rese iolent behavior.Our work focuses on the more general hypothesi hat m. standard on another over ng n of many species .Third.whereasG kevicius et al.'s exper The male ire of strategi in a elf-reported willingnes avior.Although e to enga ep.c nd to limit intra 197 whe phys the ntext of risky behaviors that oc n is not a beh 2007)ot P din the 00 the I-repor which tend to p 1999)The current work is the first to examine effects of matins motives on aggressive behavior 988Lc d to be att to socially d .1985)and socially Dominance striving and male Aggression nd t that it is evolution psychology men' it occurs,but psychologica ext of mating is not only to harm another person. t is intended to harm spec tha ctivate tors one's l Th 2009.1iu end in itself.but rathe a means to attainine social dominance Tha expect that violence among men may be mos ht topromot reproductiv ne many animal spe male ments have luring mating sea (Archer 2006).a time when mating Ronev &D help men in ase their level of socia e,aggressive behavior also diverts energy from the pur th nen.Existing experimental idence for this hypothesis is ted by ageresionistheorizcdtobolSierre ductiv inske ca(2009. uld lead t on the self-presentational functions of mating-induced aggre npetitor primarily when their social dominanc sat stake.Mor actvationof how of a male audie m an evoluti of ac ving dominance are readily avail Daly.1985)
pregnancy and childbirth. Women’s relatively higher level of obligatory parental investment limits men’s access to mates by skewing the operational sex ratio, which represents the proportion of fertile females to sexually active males (Glutton-Brock & Vincent, 1991). Due to the length of pregnancy and women’s limited lifetime reproductive capacity, the number of men motivated to find sexual partners typically far exceeds the number of fertile women. Men’s reproductive access is further limited by women’s high mating standards. Because women are obliged to invest heavily in their offspring, they tend to be more selective than men when choosing mates (Buss & Schmitt, 1993). Women’s high mating standards cause men to compete with one another over access to mating opportunities (Geary, 1998). The males of many species use a repertoire of strategies— including violence—to compete with other males, thereby increasing their access to mating opportunities (Archer, 2009). Like other sexually selected traits, aggression is theorized to have been sexually selected through both intrasexual competition and intersexual selection. Men use aggression to compete directly with other men and to limit other men’s access to mates (i.e., intrasexual competition). Men also use aggression to signal qualities that are desired by the opposite sex (i.e., intersexual selection). Although aggression is not a behavior that women necessarily find attractive on its own, men use aggression to increase their level of social dominance, a characteristic upon which women tend to place a premium (Buss, 1988; Li, Bailey, Kenrick, & Linsenmeier, 2002; Sadalla, Kenrick, & Vershure, 1987; Schmitt & Buss, 1996). Across many societies, women tend to be attracted to socially dominant men (Buss, 1988; Li & Kenrick, 2006; Maner, DeWall, & Gailliot, 2008; Turke & Betzig, 1985) and socially dominant men tend to achieve relatively high levels of reproductive success (Betzig, 1986, 1992). Theories from evolutionary psychology suggest that men’s historical need to compete with other men over access to mates causes them to be more violent than women, in general. However, contemporary evolutionary psychological research also suggests that although humans are equipped with mechanisms designed to enhance their reproductive success, those mechanisms become operative particularly in situations that activate proximate mating motives (e.g., Maner, Gaillot, Rouby, & Miller, 2007, Maner, Miller, Rouby, & Gaillot, 2009). Thus, there is reason to expect that violence among men may be most prevalent when proximate mating motives are active. Indeed, among many animal species, male aggression reaches its zenith during mating season (Archer, 2006), a time when mating motives are presumably most salient. Because aggression is theorized ultimately to serve matingrelated functions, we hypothesized that activating a mating motive would increase men’s tendency to behave aggressively toward other men. Existing experimental evidence for this hypothesis is limited. To date, the most compelling experimental study demonstrating the effect of mating motives on aggression was reported by Griskevicius et al. (2009). Our research differs from their work in a number of important respects. First, Griskevicius et al. focused on the self-presentational functions of mating-induced aggression—they reported an experiment suggesting that activation of a mating motive led men to display aggression, but only in the presence of a male audience. From an evolutionary perspective, mating-induced aggression in humans and other species is designed not only to help males self-present; it serves as a means through which males directly dominate one another, regardless of who is watching. Thus, our research examines mating-induced aggression in the absence of self-presentational concerns and focuses more squarely on the hypothesis that the desire to assert one’s dominance underlies mating-induced male aggression. Second, their research focused on aggressive responses to an explicit insult (e.g., when someone spills a drink on you and fails to apologize), whereas our research does not rely on insults to trigger violent behavior. Our work focuses on the more general hypothesis that mating motives lead men to adopt a fundamentally aggressive stance toward other men, even in the absence of an audience or insulting provocation. Third, whereas Griskevicius et al.’s experiment examined men’s self-reported willingness to act aggressively in a hypothetical situation, we examine actual aggressive behavior. Although examining self-reported willingness to engage in hypothetical aggression reflects a valuable step, classic research on the intention– behavior gap shows that self-reports do not necessarily translate into actual behavior (e.g., Fishbein & Ajzen, 1975), especially when that behavior causes physical pain or carries the cost of potential retaliation (see Baumeister, Vohs, & Funder, 2007). Indeed, in the context of risky behaviors that occur in the heat of the moment, self-reported behavioral intentions often only weakly predict actual behavior (Sheeran, Abraham, & Orbell, 1999). The current work is the first to examine effects of mating motives on aggressive behavior. Dominance Striving and Male Aggression A commonly used definition of aggression states that it is a behavior intended to harm another individual (Archer, 2009). This definition is useful for classifying aggression when it occurs, but it is mute to the motivational bases of aggression. From a functionalist perspective, aggression in the context of mating is not only intended to harm another person, it is intended to harm specific others (same-sex romantic competitors) for specific reasons (see Griskevicius et al., 2009). These reasons include subordinating competitors to increase one’s level of social dominance. This perspective suggests that mating-induced male aggression is not an end in itself, but rather a means to attaining social dominance. That is, aggression is thought to promote reproductive success because it increases a man’s dominance over other men. Indeed, several experiments have demonstrated that priming mating goals activates concepts related to status (Griskevicius et al., 2007; Roney, 2003; Wilson & Daly, 2004). Although aggression can help men increase their level of social dominance, aggressive behavior also diverts energy from the pursuit of other goals and can lead to injury or death (Daly & Wilson, 1988). These costs imply that men should engage in aggression selectively. Because aggression is theorized to bolster reproductive success in part by increasing men’s social dominance, we hypothesized that mating motives would lead men to aggress against a competitor primarily when their social dominance is at stake. More specifically, we predicted that men primed with mating would show increases in aggression toward other men only when no other, less costly ways of achieving dominance are readily available (cf. Wilson & Daly, 1985). 820 AINSWORTH AND MANER 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
MATING AND MALE AGGRESSION 821 The Role of Short-Term Mating Evolutionary theorie ggest that mating-induc male aggre rnExperimew manipulated the gender of the target person.W not the divi Gangestad,191).If the ulimate function aggression Experiment 1 is to sion would be oberved men displan Experiment 1 provided an initial test of the hypothesized link onships becaus such men seek multiple par behavioral measure athe mitting to on for shor-ter Metho ially likely to display social do Participants. Fify-one men completed the experiment for ourse credit. pursuing a short-term strategy tend to engage in more dir eey (Simn on Ganeestad.Christensen Leck 1999)Such ent with them feel sexual desire an d wrote in detail about an exp Snyder.Kirkpa nvolving inte d to the d that mat made them feel happy and wrote at a time of int term mating strategy.reltive to a long term mating strategy The Current Research in mood o ts,we manipulated n ting motives s and measured ag of mood and arousal ng a n e told they ould increase aggressive beha nating primes an ong women ach of 25 trials.pa cipants reacte se set by further evidence of the mating-related functions o nd the duration of the noise blast tha would be deli d to thei nderlies mating-related aggres ive behavior in men.Theref aggression).As in pro be fm n Experiment 3 we exa mined two additional moderating vari Particinants set the volume and duration for the first trial before ces in men's ion:Gangestad sin n Gangestad ner.Thu ng i ting prim t the egy.Second.ourf work implies that er.This task therefore provide sures o heing-in uld not exne mating motives to increase men's aggression toward women. dardized duration of the noise blast set by the participant on the
The Role of Short-Term Mating Evolutionary theories suggest that mating-induced male aggression may depend on individual differences in men’s orientation toward short-term mating versus long-term mating (see Simpson & Gangestad, 1991). If the ultimate function of aggression is to increase access to mates, we hypothesized that the use of aggression would be observed primarily among men displaying a shortterm mating strategy. Access to mates may be a more chronic reproductive constraint for men pursuing short-term sexual relationships because such men seek multiple partners rather than committing to one mate for an extended period. To increase access to mates, men with a preference for short-term mating may be especially likely to use aggression to display social dominance. Indeed, displays of dominance have been shown to serve shortterm mating goals, in particular (Sundie et al., 2011), and men pursuing a short-term strategy tend to engage in more direct intrasexual competition tactics than men pursuing a long-term strategy (Simpson, Gangestad, Christensen, & Leck, 1999). Such findings are consistent with evidence that women prefer dominant men primarily in the context of short-term mating (Gangestad, Simpson, Cousins, Garver-Apgar, & Christenson, 2004; Snyder, Kirkpatrick, & Barrett, 2008). We therefore predicted that mating primes would increase aggression more strongly in men pursuing a shortterm mating strategy, relative to a long-term mating strategy. The Current Research The current research tested the overarching hypothesis that mating motives elicit aggressive behavior in men. Across three experiments, we manipulated mating motives and measured aggression toward a same-sex partner using a noise-blast paradigm. Based on evolutionary theories of intrasexual competition, we predicted that the mating primes would increase aggressive behavior in men. Because aggression does not serve the same matingrelated functions for women, we anticipated no effects of the mating primes among women. In addition to the moderating effect of participant gender, we examined three additional moderating variables in these studies. These moderating variables were intended not only to identify theoretically meaningful boundary conditions but also to provide further evidence of the mating-related functions of aggressive behavior. First, we examined the moderating role of social dominance. Our theoretical framework implies that dominance-striving underlies mating-related aggressive behavior in men. Therefore, if men are able to achieve social dominance in some other (less provocative) way, one would expect the effects of mating motives on aggression to be weakened or eliminated. We tested this hypothesis in Experiment 2. In Experiment 3, we examined two additional moderating variables. First, we examined individual differences in men’s orientation toward short-term versus long-term mating (i.e., sociosexual orientation; Gangestad & Simpson, 1990; Simpson & Gangestad, 1991). We expected that mating primes would increase aggressive behavior more strongly in men pursuing a short-term than a long-term mating strategy. Second, our framework implies that mating-induced aggression is designed to achieve dominance over other men (i.e., intrasexual competition). One would not expect mating motives to increase men’s aggression toward women. Therefore, in Experiment 3, we also manipulated the gender of the target person. We predicted that the mating prime would increase men’s aggression toward another man, but not a woman. Experiment 1 Experiment 1 provided an initial test of the hypothesized link between mating motives and male aggression. After undergoing a mating prime, male participants performed a noise blast aggression task, a well-validated behavioral measure of aggression. Method Participants. Fifty-one men completed the experiment for course credit. Procedure. Participants first completed the priming procedure, which consisted of an essay writing task from previous research (Fitzsimons & Bargh, 2003; Maner et al., 2007). Participants assigned to the mating condition listed five things that made them feel sexual desire and wrote in detail about an experience involving intense sexual desire for approximately 10 min. Participants assigned to the control condition instead listed five things that made them feel happy and wrote about a time of intense happiness. The control condition was taken from previous research (Maner et al., 2007) and was designed to match the positive valence and emotional intensity of the sexual desire essay. The control condition helped rule out the possibility that any effects of priming condition would be due merely to changes in mood or arousal. Following the priming-procedure, participants completed the Brief Mood Introspection Scale (Mayer & Gaschke, 1988), providing measures of mood and arousal. Next, participants were told they would complete an auditory reaction-time task with an ostensible partner and were shown a picture of a male confederate. The task consisted of the noise-blast task, a well-validated behavioral aggression measure used in many previous experiments (e.g., Bushman & Baumeister, 1998; Giancola & Zeichner, 1995). On each of 25 trials, participants reacted as quickly as possible to a tone played through headphones by clicking within a box on the computer screen. The loser of each trial was forced to listen to a painful blast of white noise set by their partner. Before each trial, participants chose both the volume and the duration of the noise blast that would be delivered to their partner if the participant won the trial. Selection options for both the volume and duration of the noise blast ranged from 0 (no aggression) to 10 (maximum aggression). As in previous research, participants were automatically assigned to lose half the trials. The volume and duration of the noise blast that participants heard after losing were identical across participants and increased incrementally throughout the task. Participants set the volume and duration for the first trial before receiving any noise blasts from their partner. Participants (ostensibly) lost the first trial and received the noise blast set by their partner. Thus, on all but the first trial, participants were reacting in part to noise blasts (ostensibly) delivered by their partner, and they thought their behavior could elicit aggressive responses from their partner. This task therefore provides two distinct measures of aggression (unprovoked and provoked). Unprovoked aggression was computed by summing the standardized intensity and standardized duration of the noise blast set by the participant on the MATING AND MALE AGGRESSION 821 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
822 AINSWORTH AND MANER blast task which before participant Experiment 2 scores were uted by summing the standardized average in. xpe ardized a blasts set by task e feed k that they ore report results measures of aggress e over their partner,they would not be as motivated t Results and Discussion o a ma ng pnme with S.W We predicted that the ( with inc nsgg nance effect of the mating prime d aggre no effect of priming condition for provoked ag Method There w 42 Participants. male under or c ments ancillary analyses to test mood or antial suspicio during a postexperimental probe).Seventy ot caused merely by changes in mood or arousal no differ ved for arousal (P Procedure. ,49) 21.Ad Participants arrived and were told that they would th an os and sal controlled was only very slightly ted three ed.F(1.47) 36206,n=0. ndings ld be ion among men.although this effect was limited to measure of unprovoked aggression. the Remote ce of this task the experimenter described the test as mea 6e (and Standard Deviations)of Unstandardized Aggression Nex s of tra as po Unprovoked Provoked s.In the final compe ng ve task. pticipantswer 8689 1988出 s provid ne of the best measures of overall 10.496.09 ssigned to the mti onditi listed fiv npetitive feedback t 3 剧 ndition completed the same task but inst listed and wrot ving the female target 868 vere primed with mating 882 on. ct the radioimmunoassays
first trial of the noise blast task, which occurred before participants received any noise blasts from the partner. Provoked aggression scores were computed by summing the standardized average intensity and standardized average duration of the noise blasts set by the participant for the remaining 24 trials. We had no a priori predictions about whether the predicted increases in aggression would apply to unprovoked versus provoked aggression. We therefore report results for both measures of aggression.2 Results and Discussion We predicted that the mating prime (vs. control prime) would increase men’s aggression toward a same-sex partner. We tested for this effect on unprovoked and provoked aggression. Men who completed the mating prime (M 0.43, SD 1.55) showed more unprovoked aggression toward a partner than men who completed the control prime (M – 0.45, SD 1.48), t(49) 2.09, p .04. There was no effect of priming condition for provoked aggression (p .42). See Table 1 for unstandardized means and standard deviations of the aggression measures in the three current experiments. We conducted ancillary analyses to test whether mood or arousal differed by priming condition to verify that effects were not caused merely by changes in mood or arousal. No differences were observed for mood (p .49) or arousal (p .21). Additionally, the effect of priming condition for unprovoked aggression with mood valence and arousal controlled was only very slightly reduced, F(1, 47) 3.62, p .06, 2 .07. Findings from Experiment 1 provided initial evidence that a mating prime increased aggression among men, although this effect was limited to a measure of unprovoked aggression. Experiment 2 Experiment 2 was designed to isolate the hypothesized mechanism—a desire to dominate intrasexual competitors— underlying mating-induced male aggression. This was accomplished by having participants complete a competition with their partner prior to the behavioral aggression task. Some participants were randomly assigned to receive feedback that they had won the competition. We reasoned that because those participants had already achieved dominance over their partner, they would not be as motivated to respond to a mating prime with increased aggression. That is, we expected participants to respond to the mating prime (vs. control) with increased aggression, but only when they had been given no feedback about the competition. We expected that achieving dominance via winning the competition would weaken or eliminate the effect of the mating prime. Method Participants. Eighty-one male undergraduates participated for course credit. Eleven participants were excluded (five participants knew their partner or the experimenter; four did not follow instructions during the aggression paradigm; and two expressed substantial suspicion during a postexperimental probe). Seventy participants remained. Procedure. Participants arrived and were told that they would be completing several competitive tasks with an ostensible partner. After viewing a picture of a male confederate, participants completed three competitive tasks and were told their performance would be compared with the performance of their partner. In the first competitive task, participants were given 3 min to correctly identify as many word associations as possible from the Remote Associates Test (Mednick, 1968). To heighten the perceived importance of this task, the experimenter described the test as measuring verbal intelligence, quick thinking, and overall competence that tends to predict future success in private and professional domains. Next, participants performed a “creativity task” in which they were asked to list as many modes of transportation as possible in 90 s. The task was described as being predictive of future salary and career success. In the final competitive task, participants were asked to squeeze a handgrip as long as possible to measure physical strength. Participants were told that handgrip measurements provide one of the best measures of overall body strength. Participants then completed the priming procedure from Experiment 1. Participants assigned to the mating condition listed five things that made them feel sexual desire and wrote about one specific event in greater detail. Participants assigned to the control condition completed the same task but instead listed and wrote about things that made them feel happy. Following the priming procedure, the experimenter delivered feedback to the participant about the competition. Participants who were primed with mating were randomly assigned to two competition feedback conditions. In the competitive-feedback condition, participants received their 2 In addition to the procedure detailed here, participants also provided saliva samples before the priming procedure and after the noise blast task. These samples were intended to examine the role of testosterone in male aggression. Unfortunately, the salivary samples were unusable due to a malfunction of the gamma counter used to conduct the radioimmunoassays. Table 1 Means (and Standard Deviations) of Unstandardized Aggression Variable Unprovoked Provoked Experiment 1 Control 6.76 (3.26) 10.39 (3.71) Mating 8.58 (3.17) 9.58 (3.21) Experiment 2 Control/No feedback 8.91 (4.14) 10.18 (3.04) Mating/No feedback 11.89 (3.90) 11.34 (2.28) Mating/Competitive feedback 9.52 (3.90) 10.49 (3.09) Experiment 3 Men with male target Control 7.00 (3.12) 9.78 (2.58) Mating 9.37 (3.39) 11.25 (3.04) Men with female target Control 7.32 (2.81) 9.36 (3.35) Mating 6.57 (3.46) 9.59 (3.13) Women with male target Control 7.74 (3.30) 9.05 (2.87) Mating 8.57 (3.91) 9.37 (3.13) Women with female target Control 7.71 (2.15) 8.68 (2.59) Mating 8.00 (2.56) 9.29 (2.63) Note. Aggression scores reflect the volume and duration of the noise blast and were indicated on a scale ranging from 0 (no aggression) to 20 (maximum aggression). 822 AINSWORTH AND MANER 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.
MATING AND MALE AGGRESSION 823 scores on each of the competitive tasks and the scores of their (M..)were significantly lss aggressive than ach of men primec etitive task In the no-competitiv ondition. 0 no told how well they ison to thei d that they Neith on to the partn Par ipants in the control (non ating)c voked a no-competiv maine hei elative to their part Compared with men in the control ndition,men who com ating prime ed a m wihndreceivednofed ck.and (c)control prime petitivefeedhctri Maver aschke.1988)providi s measures of mood and ggrc therefore who had affirmed their dominance over their pa Results man's dominance over other men. Experiment 3 their tive to m d that ld be allowing us t erating effe that is. d the se o tha ed in the a differed cted o voke ession scores did not differ we sed to de We cted the effect of the mating prime on The first cor 91) about the competitio with E hypothesized mating prime 0.75 SD ants.(b)this incre me displ d me n than restricted men.The hypo ong would provide strong evidence for the functiona ed effect of mating motives on aggres d the tition 57. Method The final planped con for differe s in ke Participants.One hundred eighty undergraduates partic ng pthe ourse crec competition.Men primed with mating who won the competition participants (82 women)
scores on each of the competitive tasks and the scores of their ostensible partner. The partner’s scores were fabricated so that the participant performed better than the partner on each of the competitive tasks. In the no-competitive-feedback condition, participants received their own scores on each of the competitive tasks but were not told how well they scored in comparison to their partner. Instead, those participants were told that they would find out at the end of the experiment how well they scored in comparison to the partner. Participants in the control (nonmating) condition received feedback identical to those in the no-competitivefeedback condition; they received their own scores but no information about how well they had done relative to their partner. In sum, there were three experimental conditions: (a) mating prime with no competitive feedback, (b) mating prime with competitive feedback, and (c) control prime with no competitive feedback. Participants then completed the Brief Mood Introspection Scale (Mayer & Gaschke, 1988), providing measures of mood and arousal. Finally, participants completed the noise-blast aggression paradigm, which provided measures of unprovoked and provoked aggression. Results We expected men who completed the mating prime and who did not receive competitive feedback to demonstrate higher levels of aggression toward their partner, relative to men who completed the control prime. This would replicate the pattern from Experiment 1. However, we also predicted that this effect would be eliminated by the presence of competitive feedback; that is, we expected aggression among men in the mating prime/competitive feedback condition to be equivalent to that observed in the control condition. To test these predictions, we first conducted two omnibus analyses of variance to determine whether unprovoked aggression or provoked aggression scores differed by experimental condition. The omnibus tests indicated significant differences in unprovoked aggression among the three experimental conditions, F(2, 67) 3.32, p .04, 2 .09. Provoked aggression scores did not differ significantly by condition (p .60). Three planned contrasts were used to deconstruct the significant omnibus test for unprovoked aggression. The first contrast tested for differences in unprovoked aggression among men in the mating and control condition who received no feedback about the competition. Consistent with Experiment 1, when participants received no feedback about the outcome of the competition, men who completed the mating prime (M 0.75, SD 1.49) displayed more aggression than men who completed the control prime (M – 0.41, SD 1.58), F(1, 67) 6.14, p .02, 2 .08. The second planned contrast tested for differences in aggression between participants who completed the mating prime and were told they won the competition and participants who completed the control prime. We predicted that unprovoked aggression scores would not differ among these groups. Consistent with the prediction, participants in the mating condition who believed they won the competition (M – 0.17, SD 1.52) showed no increases in aggression compared with control participants (M – 0.41, SD 1.58), F(1, 67) .33, p .57, 2 .01. The final planned contrast tested for differences in unprovoked aggression among participants who completed the mating prime, and either did or did not receive feedback that they won the competition. Men primed with mating who won the competition (M – 0.17, SD 1.52) were significantly less aggressive than men primed with mating who received no feedback about the competition (M 0.75, SD 1.49), F(1, 67) 4.01, p .05, 2 .06. As in the previous experiment, we tested for differences across conditions in mood valence and arousal to rule out the possibility that these factors could account for the observed effects. Neither mood valence (p .18), nor arousal (p .10), differed by condition. Moreover, the effect of condition on unprovoked aggression remained significant even after controlling for mood valence and arousal, F(2, 65) 3.52, p .04, 2 .10. Compared with men in the control condition, men who completed a mating prime and received no feedback about the outcome of the competition with their partner demonstrated higher levels of unprovoked aggression. This pattern is consistent with the finding from Experiment 1 and supports the hypothesis that mating motives increase aggressive behavior in men. However, this increase in aggression was observed only when men were not told about the outcome of the competition. Men who won the competition, and therefore who had affirmed their dominance over their partner, showed no increase in aggression. This supports the hypothesis that mating-induced male aggression is intended to increase a man’s dominance over other men. Experiment 3 Experiment 3 was designed to replicate and extend the previous experiments in three main ways. First, the sample included participants of both sexes, allowing us to test for moderating effects of sex. We expected men, but not women, to respond to the mating prime with increased aggression. Second, we manipulated the sex of the participants’ partner. In the previous experiments, participants were always led to believe that they had a same-sex partner. Our framework implies that mating-induced male aggression functions as a means of intrasexual competition. Therefore, although a mating prime was expected to increase men’s aggression toward a male partner, we did not expect the prime to increase aggression toward a female partner. Third, we examined moderating effects of participants’ sociosexual orientation (Simpson & Gangestad, 1991). We expected the effect of the mating prime on increased aggression to be especially pronounced among sexually unrestricted men—those who tend to pursue a short-term mating strategy. In sum, we hypothesized that (a) a mating prime would increase aggressive behavior among male participants, but not female participants, (b) this increase would be specific to men interacting with a male partner (not a female partner), and (c) the increased aggression would be more pronounced among sexually unrestricted men than restricted men. These hypotheses thus imply a four-way interaction among experimental prime, participant sex, partner sex, and sociosexual orientation. Evidence for this fourway interaction would provide strong evidence for the functional specificity of the hypothesized effect of mating motives on aggression. Method Participants. One hundred eighty undergraduates participated for course credit. Three participants who correctly guessed that the partner was a confederate were excluded, leaving 177 participants (82 women). MATING AND MALE AGGRESSION 823 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.