Intersexual aggression and male sexual activity in captive rhesus macaques

Rape has been posited to be an outgrowth of male reproductive strategies. Forced copulations may have evolved as a consequence of the low parental investment made by males in producing and raising offspring. We designed a laboratory experiment which paired rhesus macaque males with females in order to assess the influence of intersexual aggression on male sexual activity. Younger and older adult males had comparable levels of sexual behavior, but younger males were more aggressive towards females than were older males. In addition, females threatened younger males more than older males. Male attacks on females did not result in sexual intercourse. On the contrary, a negative correlation existed between male aggression towards females and male success at achieving intromissions. Female aggression towards males appeared to be an effective tactic which reduced the chances of sexual intercourse. We conclude that intersexual aggression acts either as a mechanism of dominance assertion or as a means to increase spatial distance between individuals. These data do not support the idea that rape in humans has an evolutionary foundation derived from male reproductive strategies.     

Aggressive Behavior and Peer Social Status of Elementary School Children

The relation between aggression and peer social status was investigated in a group of 238 third-through fifth-grade children. Peer social status refers to the degree to which a child is accepted by his or her peer group. By asking children to nominate peers they “like most” and “like least,” one can identify children who are popular, rejected, neglected, or viewed as average within their peer group. Results indicated low to moderate correlations between peer-nominated aggression and global indices of social acceptance. More specifically, it was found that aggressive children largely comprised the rejected and average social status groups, but not the popular or neglected groups. Furthermore, analyses indicated that according to both peers and teachers, aggressive/rejected children showed academic and social-skill deficits, whereas aggressive children of average peer status exhibited adequate adjustment similar to that of nonaggressive/average-status children. These results suggest the importance of considering peer social status when identifying aggressive children in need of intervention and in determining which skill deficits to address. In addition, knowledge of an aggressive child's peer status might be useful in enhancing the predictability of adult adjustment.     

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.     

Quantitative chromatographic profiling of odours associated with dominance in male laboratory mice

Triads of male NMRI mice were housed together and dominance hierarchies allowed to form. At age 19 weeks the mice were ranked on the basis of wins in spontaneous aggressive encounters, and whole-body volatiles were sampled by the dynamic solvent effect and quantitatively analysed by capillary gas chromatography. At age 26 weeks the mice were again ranked on the basis of wins in aggressive encounters, number of aggressive encounters initiated, and scent marking patterns, and whole-body volatiles were sampled and analysed. Chromatographic odour profile ranks agreed perfectly with aggressive initiator ranks and poorly with encounter winner ranks. Eight components of the whole-body odour were identified by gas chromatography-mass spectrometry; two of these are known semiochemicals. The results demonstrate that murine semiochemicals are accessible to quantitative analysis at the level of the individual.     

Is indirect aggression typical of females? gender differences in aggressiveness in 11- to 12-year-old children

Gender differences regarding aggressive behaviour were investigated in 167 school children, 11 to 12 years of age, through peer-rating techniques supported by self-ratings and interviews. The social structure of the peer groups also was studied. The principal finding was that girls made greater use of indirect means of aggression, whereas the boys tended to employ direct means. Gender differences in verbal aggression were less pronounced. The social structure of peer groups was found to be tighter among girls, making it easier for them to exploit relationships and harm their victims by indirect manipulative aggression. Because indirect aggression has rarely been satisfactorily studied with tests of aggression, this finding may help to explain 1) the generally lower correlation found between peer-rated and self-rated aggression in girls than among boys (indirect means not being so readily recognized by the subject as a kind of aggression) and 2) the low stability of aggressiveness in girls often found in developmental studies.     

Facet-level analysis of the relations between personality and laboratory aggression

Multiple reviews and meta-analyses have identified the low pole of the Five-Factor Model (FFM) Agreeableness (also called Antagonism) as the primary domain-level personality correlates of aggression across self-report and behavioral methodologies. In the current study, we expand on this literature by investigating the relations between FFM facets and aggressive behavior as measured by laboratory competitive reaction time tasks (CRTTs). Across three samples (total N = 639), we conducted weighted mean analyses, multiple regression analyses, and dominance analyses to determine which FFM facets were the strongest predictors of aggression within and across domains. These analyses suggested that facets of Agreeableness were among the strongest consistent predictors of CRTT aggression, including Sympathy (r = −.21) and Cooperation (r = −.14), but facets from other FFM domains also yielded meaningful relations (e.g., Anger from Neuroticism; r = .17). We conclude by discussing these results in the context of controversies surrounding laboratory aggression paradigms and emphasizing the importance of considering small effect sizes in the prediction of societally harmful behavior like aggression.     

Internalizing problems and their impact on the relation between callous-unemotional traits,narcissism, and aggression

Narcissism and callous-unemotional (CU) traits have demonstrated relations with youth aggression across studies. However, different forms of narcissism and internalizing problems may exacerbate the relation between CU traits and aggression. To that end, the current study examined the degree to which interactions among internalizing problems, CU traits, and dimensions of narcissism related to aggression in a sample of 219 adolescents (83.1% males), ages 16–19, enrolled in a military-style residential program. Consistent with previous research, psychopathy-linked narcissism significantly moderated the relation between CU traits and aggression. Addtionally, self-reported aggression was highest among adolescents who endorsed high levels of CU traits, psychopathy-linked narcissism, and internalizing problems. The same pattern of results was not evident for other forms of narcissism. These results suggest that internalizing problems further increase the probability of aggression among adolescents with psychopathic tendencies (i.e., CU traits, psychopathy-linked narcissism). Further implications are discussed.     

Cyberbullying,cyber aggression,and cyber victimization in relation to adolescents’ dating and sexual behavior: An evolutionary perspective

This study examined adolescents’ cyberbullying, cyber aggression, and cyber victimization from an evolutionary perspective, extending previous research showing that traditional forms of bullying, aggression, and victimization are associated with reproductively relevant outcomes. Consistent with hypotheses based on theory and research linking bullying and aggression to intrasexual competition for mates, results indicated that cyber victimization was positively associated with a number of dating and sexual partners. Findings for cyber aggression were more complex, depending on the degree of cyber victimization experienced by the perpetrator, and the balance of power between the perpetrator and victim. Specifically, nonbullying cyber aggression by perpetrators with equal or less power than the victim had stronger positive relations with the number of dating or sexual partners when perpetrators experienced a high level of cyber victimhood. In contrast, cyberbullying by perpetrators with more power than the victim was negatively associated with the number of dating partners when the perpetrators’ exposure to cyber victimization was low. Although cyber aggression and cyber victimization are new forms of aggression that involve the use of modern electronic devices, the results of this study demonstrate the usefulness of viewing this behavior from an evolutionary perspective and show that adolescents are likely to use cyber aggression against rivals in the context of intrasexual competition for mates.     

A combination of combat experience,early abduction,and severe traumatization fuels appetitive aggression and violence among abductees of rebel war in Northern Uganda

Individuals who perpetrate violence may likely perceive violence as appealing and infliction of violence to derive pleasure is termed as appetitive aggression. Individuals who were abducted as children into an armed group often experience a higher number of traumatic event types, that is traumatic load and are usually socialized in a violence-endorsing environment. This study aims to investigate the interaction between age at initial abduction with that of traumatic load, and their influence on appetitive aggression along with perpetration of violent acts by former members of an armed rebel group of both sexes. Semi-structured interviews were conducted among a target group of formerly abducted rebel-war survivors (including participants with and without combat experience) from Northern Uganda. Participants included 596 women and 570 men with N = 1,166 (M_age = 32.58, SD_age = 9.76, range: 18–80 years). We conducted robust linear regression models to investigate the influence of age at initial abduction, traumatic load, combat experience, and biological sex on appetitive aggression as well as their perpetrated violent acts. Our study shows, appetitive aggression and the number of perpetrated violent acts were specifically increased in individuals who were abducted young, experienced several traumatic events in their lifetime, and with previous combat experience. For perpetrated violence men showed increased levels whereas for appetitive aggression the association was independent of biological sex. Therefore, early abducted individuals with a higher traumatic load, who have combat experience, need to be given special intervention to prevent any further violence.     

Making Americans Feel Great Again? Personal Significance Predicts Political Intentions of Losers and Winners of the 2016 U.S. Election

Reactions of losers and winners of political elections have important consequences for the political system during times of power transition. In four studies conducted immediately before and after the 2016 U.S. presidential elections, we investigated how personal significance induced by success or failure of one's candidate is related to hostile versus benevolent intentions toward political adversaries. We found that the less significant supporters of Hillary Clinton and supporters of Donald Trump felt after an imagined (Study 1A) or actual (Study 2) electoral failure the more they were willing to engage in peaceful actions against the elected president and the less they were willing to accept the results of the elections. However, while significance gain due to an imagined or actual electoral success was related to more benevolent intentions among Clinton supporters (Study 1B), it was related to more hostile intentions among Trump supporters (Studies 1B, 2, and 3).