Sex and aggression during rhesus monkey group formation

Observational data from 16 newly formed social groups of rhesus monkeys were analyzed to identify patterns of behavior that correlated with the frequency and intensity of aggression directed toward females. The results revealed significant correlations between heterosexual behavior and female-female noncontact aggression and between female homosexual behavior and female-female contact aggression. The role of female homosexual behavior and its relationship to aggression in the formation of new groups is discussed.     

Affiliative and aggressive dimensions of dominance and possible functions during early adolescence

In this paper, the role of aggression and affiliation in the development and possible functions of dominance during early adolescence is reviewed. It is suggested that both aggression and affiliation relate to dominance at different phases in the formation of new group structures. This conclusion is based on ethological theory and data from human and nonhuman primates. In terms of function, it was noted that dominance should be considered in relation to some outcome, not as an end in its own right. Further, there are probably different goals in different developmental periods. Heterosexual relationships seem to be an important resource for the period of adolescence. Consistent with theory, both affiliative and aggressive dimensions of dominance predict boys' heterosexual relationships. Suggestions for future research are made.     

Impact of artificial fissioning and social networks on levels of aggression and affiliation in primates

Levels of aggression may be affected by stability of social relationships or by population density. A number of studies of nonhuman primates have indicated that spatial density influences agonistic activity levels less than does social density. Artificial fissioning of a captive troop of rhesus macaques was undertaken and the resultant differences in patterns of aggression and affiliation were examined. If population density has a major effect on levels of aggression, then fissioning will result in a decrease in aggression; if social stability has a major effect on levels of aggression, then fissioning is likely to be accompanied by an increase in aggression. An increase in rates of both aggressive and affiliative behavior resulted from artificial troop fissioning. These findings concur with other studies that have concluded that social stability is a more important determinant of primate aggression than is population density. Nonhuman primates use affiliative mechanisms to adjust their behavior when population density increases such that potentially adverse consequences of crowding are avoided.     

Body size as a determinant of aggression during heterosexual encounters in hormone-treated gonadectomized pigs

Aggressive and sexual behavior was studied in 5-minute paired encounters between testosterone-treated castrated boars and estrogen-treated ovariectomized gilts. The boars were either 15 kg heavier (N = 6), or lighter (N = 6), than the gilts (N = 8). Tests were carried out over a 4-week period, during which time each boar was paired once with each gilt; the procedure was replicated over a further 4 weeks. Gilts usually initiated the aggression, especially in the first 4-week period; however, the degree of aggression was positively correlated with body size, irrespective of sex. Aggression was reduced in the second 4-week period in both sexes in tests with large, but not with small, boars. Large boars were more sexually active than small boars, and their sexual performance improved markedly with time, unlike that of the small boars. Champing was positively correlated with aggression duration in pigs of both sexes, and salivation was seen more often in boars than gilts.     

Homophobia and physical aggression toward homosexual and heterosexual individuals

This study examined the relationship between homophobia (defined as self-reported negative affect, avoidance, and aggression toward homosexuals) and homosexual aggression. Self-identified heterosexual college men were assigned to homophobic (n = 26) and nonhomophobic (n = 26) groups on the basis of their scores on the Homophobia Scale (HS; L. W. Wright, H. E. Adams, & J. A. Bernat, 1999). Physical aggression was examined by having participants administer shocks to a fictitious opponent during a competitive reaction time (RT) task under the impression that the study was examining the relationship between sexually explicit material and RT. Participants were exposed to a male homosexual erotic videotape, their affective reactions were assessed, and they then competed in the RT task against either a heterosexual or a homosexual opponent. The homophobic group reported significantly more negative affect, anxiety, and anger-hostility after watching the homosexual erotic videotape than did the nonhomophobic group. Additionally, the homophobic group was significantly more aggressive toward the homosexual opponent, but the groups did not differ in aggression toward the heterosexual opponent.     

Friendship Selection and Influence Processes for Physical Aggression and Prosociality: Differences between Single-Sex and Mixed-Sex Contexts

The present study examined to what extent selection and influence processes for physical aggression and prosociality in friendship networks differed between sex-specific contexts (i.e., all-male, all-female, and mixed-sex classrooms), while controlling for perceived popularity. Whereas selection processes reflect how behaviors shape friendships, influence processes reveal the reversed pattern by indicating how friends affect individual behaviors. Data were derived from a longitudinal sample of early adolescents from Chile. Four all-male classrooms (n = 150 male adolescents), four all-female classrooms (n = 190 female adolescents), and eight mixed-sex classrooms (n = 272 students) were followed one year from grades 5 to 6 (M _age = 13). Analyses were conducted by means of stochastic-actor-based modeling as implemented in RSIENA. Although it was expected that selection and influence effects for physical aggression and prosociality would vary by context, these effects showed remarkably similar trends across all-male, all-female, and mixed-sex classrooms, with physical aggression reducing and with prosociality increasing the number of nominations received as best friend in all-male and particularly all-female classrooms. Further, perceived popularity increased the number of friendship nominations received in all contexts. Influence processes were only found for perceived popularity, but not for physical aggression and prosociality in any of the three contexts. Together, these findings highlight the importance of both behaviors for friendship selection independent of sex-specific contexts, attenuating the implications of these gendered behaviors for peer relations.     

The roles of aggressive and affiliative behaviors in resource control: A behavioral ecological perspective

Extant literature in developmental psychology has documented the co-occurrence of aggressive and affiliative behaviors with various measures of social dominance. While these findings have been taken as evidence for the functional value of aggression, they have not been integrated into a more general theoretical frame accounting for contextual variation. In this paper the literature on aggression, agonism, affiliation, and social dominance is reviewed in light of behavioral ecological theory suggesting that different forms of competition (scramble and contest) determine, respectively, the use of affiliative and aggressive strategies. Results generally support the hypotheses advanced by this theory. In order to further integrate these findings suggestions for the study sequences of behavior, where reconciliations follow aggression, are made.     

Cooperative social coordination and aggression: Sex and strain differences in the effects of housing on gonadectomized rats with hormone replacement

Laboratory rats were used to investigate sex and strain differences in the effects of aggression on a cooperative behavior in which pairs learn to coordinate shuttling in a rectangular chamber. The level of aggression was manipulated by comparing males and females of the aggressive S3 strain and a less aggressive Sprague-Dawley-derived strain and by housing same-sex partners either together or individually (eight groups, n = 7 pairs per group). Hormone levels were stabilized by gonadectomy and daily injections of the appropriate sex hormone. The only serious coordination deficits were in individually housed males, associated with violent fighting and an extreme dominance/subordinance relationship that was not observed in females. All other groups readily learned and performed the coordination, with evidence that low and moderate levels of aggression could facilitate coordination by evoking species-typical behaviors that increased proximity, synchrony, and differentiation within pairs. The discussion focused on models of affiliative behavior in the study of aggression and the compatibility between moderate levels of aggression and cooperation.     

Cooperative social coordination and aggression: Sex and strain differences in the effects of housing on gonadectomized rats with hormone replacement

Laboratory rats were used to investigate sex and strain differences in the effects of aggression on a cooperative behavior in which pairs learned to coordinate shuttling in a rectangular chamber. The level of aggression was manipulated by comparing males and females of the aggressive S3 strain and a less aggressive Sprague-Dawley-derived strain and housing same-sex partners either together or individually (8 groups, n = 7 pairs per group). Hormone levels were stabilized by gonadectomy and daily injections of the appropriate sex hormone. The only serious coordination deficits were in individually housed males, associated with violent fighting and an extreme dominance/subordinance relationship that was not observed in females. All other groups readily learned and performed the coordination with evidence that low and moderate levels of aggression could facilitate coordination by evoking species-typical behaviors that increased proximity, synchrony, and differentiation within pairs. The discussion focused on models of affiliative behavior in the study of aggression and the compatibility between moderate levels of aggression and cooperation.     

Do Affiliative and Autonomous Styles Relate to Peer Relational Victimization and Aggression?

This study considers whether established depressogenic personal styles based on Beck’s theory of autonomy and sociotropy relate to peer relational victimization and aggression. A diverse emerging adult sample was administered a computer-based survey. Latent profile analysis revealed affiliative, autonomous, and more balanced personal styles. Autonomous and affiliative style participants reported greater peer relational aggression than balanced style participants. Peer relational victimization mediated autonomous style differences in peer relational aggression. Additionally, peer relational victimization mediated the affiliative style difference in peer relational aggression among males and depressed females. Finally, the effect of peer relational victimization on relational aggression was greatest among depressed affiliative and depressed autonomous adults. Results highlight the potential that personal styles relate to depression risk pathways for peer relational victimization and aggression.     

LGBTQ and Heterosexual Adolescents’ Use of Indirect Forms of Aggression

In this study, researchers investigated whether lesbian, gay, bisexual, transgender, and questioning (LGBTQ) adolescents use indirect aggression and exhibit prosocial behavior in their relationships at rates comparable to their heterosexual peers. In a sample of 666 college students (median age = 19.5 years), LGBTQ adolescents (N = 22) used relationally and socially aggressive behaviors at a level consistent with their heterosexual peers. This suggests that sexual orientation identification does not appear to differentially affect the use of indirectly aggressive behaviors during social interactions. There were also no differences in self-reported interpersonally mature behaviors (e.g., use of prosocial skills) exhibited by heterosexual and LGBTQ adolescents in this sample, which indicates that sexual and gender identity were also unrelated to the use of prosocial behaviors.     

Aggression Toward Gay Men as Gender Role Enforcement: Effects of Male Role Norms, Sexual Prejudice, and Masculine Gender Role Stress

ABSTRACT This study examined sexual prejudice and masculine gender role stress as mediators of the relations between male gender norms and anger and aggression toward gay men. Participants were 150 self-identified heterosexual men who completed measures of adherence to male gender role norms, sexual prejudice, masculine gender role stress, and state anger. Participants then viewed a video depicting intimate relationship behavior between 2 gay men, reported state anger a second time, and competed in a laboratory aggression task against either a heterosexual or a gay male. Results indicated that adherence to the antifemininity norm exerted an indirect effect, primarily through sexual prejudice, on increases in anger. Adherence to the status and antifemininity norms exerted indirect effects, also through sexual prejudice, on physical aggression toward the gay, but not the heterosexual, male. Findings provide the first multivariate evidence for determinants of aggression toward gay men motivated by gender role enforcement.     

Intimate Partner Violence Victimization among Heterosexual,Gay, Lesbian and Bisexual College Students: The Role of Pro-Abuse Peer Support

Most studies of peer support for intimate partner violence (IPV) at U.S. institutions of higher learning focused solely on male assaults on heterosexual women. As well, the bulk of this work only examined how all-male social networks perpetuate and legitimate this behavior. Using recent data from a survey administered at a large U.S. residential university, the main objective of this paper is to help fill a research gap by presenting findings on (1) how having peers who have perpetrated dating abuse and (2) peers’ encouragement to be abusive to dates contributes to IPV victimization in a campus lesbian, gay, and bisexual (LGB) community. The results show that LGB students report a higher rate of such victimization than heterosexual students and the two aforementioned types of pro-abuse peer support significantly predict victimization among both sexual orientation groups.     

Patterns of Physical and Relational Aggression in a School-Based Sample of Boys and Girls

The current study investigated the patterns of aggressive behavior displayed in a sample of 282 students in the 4th through 7th grades (M age = 11.28; SD = 1.82). Using cluster analyses, two distinct patterns of physical aggression emerged for both boys and girls with one aggressive cluster showing mild levels of reactive aggression and one group showing high levels of both reactive and proactive aggression. Both aggressive clusters showed problems with anger dysregulation, impulsivity, thrill and adventure seeking, positive outcome expectancies for aggression, and higher rates of bullying. However, the combined cluster was most severe on all of these variables and only the combined aggressive group differed from non-aggressive students on their level of callous-unemotional traits. Similar patterns of findings emerged for relational aggression but only for girls.     

Athletic Participation, Fraternity Membership, and Sexual Aggression Among College Men: A Meta-analytic Review

A meta-analysis of the data relating either college athletic participation or fraternity membership to attitudes and behaviors associated with sexual aggression was conducted with 29 studies which yielded 57 effect sizes. Membership in each male group was associated to a moderate extent with rape-supportive attitudes, and to a smaller extent with self-report of sexually aggressive behavior. There was much variability in the data that could be partially predicted by variables such as the size of the college, the validity of the study, and the age of the research participants. The involvement of these all-male groups in the perpetuation of hypermasculine attitudes (Mosher and Sirkin 1984) in a patriarchal culture was discussed.     

Instrumental and hostile aggression in childhood disruptive behavior disorders

An analogue task of instrumental and hostile aggression during a competitive game was evaluated in a sample of clinically-referred 8-to 12-year-old aggressive boys. Similar to a prior task in a normative sample (Having, Wallace, & La Forme, 1979), both types of aggression increased during provocation as compared to baseline, indicating the success of the provocation manipulation, with moderate correlations between the two aggressive responses. The aggressive group with attention-deficit hyperactivity disorder (ADHD) and the aggressive group without ADHD each had higher rates of instrumental aggression than controls. Only the aggressive/ADHD group had higher rates of hostile aggression than controls. Parent Child Behavior Checklist ratings indicated a modest but significant unique relationship between instrumental aggression and delinquency. The high rate of both types of aggression in the aggressive/ADHD group suggests that comorbid ADHD and aggression may result in qualitative differences in aggressive behavior. The high rate of hostile aggression in the aggressive-ADHD group supports theoretical assumptions regarding the relationship of hostile aggression to poor impulse control.This research was supported in part by grants to the first author from the Medical College of Pennsylvania, the Allegheny-Singer Research Institute, NIMH First Award (MH4682), and support from NICHD Mental Retardation Research Center Core Center Grant (DH26979); and NIMH grants (MH40364 and MH00590) awarded to the second author. The authors are grateful to Marianne Torchinsky and Abby Michaleski for assistance in data collection. Preliminary data were presented at the annual meetings of the Association for Advancement of Behavior Therapy, New York, November 1988, and the Society for Research in Child and Adolescent Psychopathology, Costa Mesa, CA, January 1990.     

Affiliation of opposite-sexed strangers

This study examined the effects of a subject's sex and affiliative tendency and the other's physical attractiveness on the cross-sexual interaction of strangers. Although previous studies showed that one's interest in an opposite-sexed other is a function of the other's physical attractiveness, the actual behavior of individuals in the presence of attractive and unattractive others had not been systematically examined. Subjects were individually placed in a 5-min waiting situation with a physically attractive or unattractive target of the opposite sex who behaved in a standard way. Conversations were recorded and subsequently analyzed; subjects also provided their impressions of the targets following the waiting period. Physical attractiveness of the opposite-sexed other did not significantly influence the subject's verbal affiliative behavior, but the combined influence of a subject's sex and affiliative tendency was predictive of cross-sexual affiliation. Although physical attractiveness did not account for differences in affiliative behavior, subjects preferred attractive over unattractive targets as potential dates or marriage partners.     

Effect of voluntary exercise on open-field behavior and on aggression in the spontaneously hypertensive rat (SHR)

In the present study we investigated the influence of voluntary exercise on exploratory behavior and on aggression in the spontaneously hypertensive rat (SHR). Twenty-four SHR (8 weeks old) were randomly assigned to either an exercise group or a sedentary control group. The animals in the exercise group exhibited a spontaneous wheel running activity of 5-6 km/day during 6 weeks. The characteristic hyperexploratory behavior of SHR was lowered in the exercise group (p less than .001) as compared to the control group. The runners also showed a tendency for less aggression. In the postexercise period, when the runners' wheels were locked, the exercise group had a significant rise in aggression (p less than .01) vs the controls. The exploratory behavior returned immediately to the level of the controls, but we found no further increase in any of the parameters measured. However, the runners showed a type of displaced aggression exhibited as digging and biting in the test cage. This evidence suggests that voluntary exercise lowers the hyperexploratory behavior and aggression in the SHR and that an abrupt stop in exercise gives an "abstinence" reaction.     

Religious Activities, Religious Orientation, and Aggressive Behavior

Theorists and clinicians have long believed that religious practice may reduce aggression and other destructive behaviors. To date, most evidence for a relationship between religiosity and aggression comes from nonexperimental studies. The purpose of this exploratory study was twofold. First, to examine experimentally whether two religious practices reduce aggressive behavior; second, to determine if specific aspects of religious orientation and spiritual transcendence are related to level of aggression, expressed under controlled laboratory conditions. Sixty-two participants assigned to one of three experimental groups (memorize Bible passages, prayer/meditation, or control group) completed a laboratory task of aggression. Participants also completed religious and spirituality instruments, along with self-ratings of aggressive disposition. Results indicated that neither memorization of biblical passages nor meditation reduced aggression. Intrinsic-oriented religiosity participants self-reported lower aggression than extrinsic-oriented participants, but no differences were found on the laboratory task of aggression. Spiritual transcendence showed no behavioral aggression differences .