iolence is clearly contagious. If youth are exposed to violence, their own risk of behaving violently increases. The violence can be real-world proximal violence or unreal violence in the mass media. Furthermore, the effects of observing violence are more than transitory. I have argued that this happens because various social cognitions and emotional reactions are acquired through observational learning and subsequently promote violent and aggressive behavior. In this presentation I present data from two types longitudinal studies. One type examines the role of observations of proximal real-world violence on subsequent aggressive behavior. The other examines the role of exposure to media violence or playing violent video games on subsequent aggressive behavior. In both studies we find that exposure over time leads to a subsequent increased risk of behaving aggressively. In both types of studies I find that the contagion effect appears to be mediated by increased fantasizing about aggression and by the acquisition of normative beliefs more accepting of aggression.

Rape of women by men might be generated either by a specialized rape adaptation or as a by-product of other psychological adaptations. Although increasing number of sexual partners is a proposed benefit of rape according to the “rape as an adaptation” and the “rape as a by-product” hypotheses, neither hypothesis addresses directly why some men rape their long-term partners, to whom they already have sexual access. In two studies we tested specific hypotheses derived from the general hypothesis that sexual coercion in the context of an intimate relationship may function as a sperm competition tactic. We hypothesized that men’s sexual coercion in the context of an intimate relationship is related positively to his partner’s perceived infidelities and that men’s sexual coercion is related positively to their mate retention behaviors (behaviors designed to prevent a partner’s infidelity). The results from Study 1 (self-reports from 246 men) and Study 2 (partner-reports from 276 women) supported the hypotheses. The Discussion section addresses limitations of this research and highlights future directions for research on sexual coercion in intimate relationships.

Debates about gun policy often focus on the least consequential issues where public opinion is most divided or on questions that have no relevance to current gun policy options (e.g., banning handguns). Several state policies designed to keep guns from high-risk individuals are effective, though their impact is muted by weak gun laws at the federal level and in other states. These policies have broad support among gun owners and across lines of political parties. Efforts to cast gun policy debates as cultural clashes between people who like guns and those that don’t, hinder our ability to seek common ground and protect public safety.

Human aggression is at once a very basic and a very complex social behavior. Aggression is basic in that it occurs in virtually everyone at one time or another and tendencies toward aggression might be present at birth. But aggression is much more complicated than such characterizations would suggest, in terms of both the biological processes that support it and the psychological processes that determine when and how it will be expressed. This talk will focus on current research investigating how two psychologically and ecologically relevant situational variables, media violence and alcohol-related cues, bias interpretation of ongoing interactions and change underlying neural and cognitive processes in ways that can increase the expression of aggressive behavior. Going beyond traditional notions of priming, the research to be presented here discusses how misattribution of accessible mental content can play a key role in explaining the often subtle and unintended consequences of exposure to situational cues on aggressive responding.

A wealth of empirical research has revealed that physical aggression 1) is one of the most stable traits in the human behavioral repertoire, 2) usually onsets early in life, and 3) evidences unusually high levels of heritability. Do these results imply that interventions aimed at eradicating physical aggression are doomed to fail? It turns out that the answer is a resounding no – such work actually has a great deal of promise. I will discuss the origins of human aggression, highlighting the roles of development, socialization, genetics, and evolution.

Youth antisocial behavior is an important public health concern impacting perpetrators, victims, and society as a whole. Although a risk factor approach has helped inform interventions for antisocial youth, these interventions work only for some youth in some contexts. Thus more basic research is needed to highlight when, for whom and how risk affects psychopathology and resilience. I will review work that we’ve done using both neurogenetics and developmental psychopathology approaches to understand these complex behaviors with a focus on mechanisms linking risk to outcomes and identifying interplay between experience and biology to demonstrate how neurogenetic approaches can help inform our understanding of youth antisocial behavior.

Attraction to violent media is high in adolescence, especially among males, and many studies have demonstrated a path from media violence use to aggressive behavior. However, there is a lack of experimental data addressing the long-term relations between media violence use and aggression, not least because assigning participants to a heavy diet of violent media over time is precluded by ethical concerns. Our research adopted an experimental approach that compared two groups of participants who were randomly assigned to an intervention designed to reduce media violence use or a non-intervention control group over a four-year period. This combined longitudinal-experimental approach facilitates the testing of causal hypotheses about the link between violent media use and aggression. Participants were 2,000 adolescents who were in 7th or 8th grade at the start of the study. A subgroup of n= 350 was assigned to a five-week class-based intervention between the first and the second data wave and were compared to a matched control group from the longitudinal sample. The efficacy of the intervention was examined at Wave 2, followed by two further assessments another 12 (Wave 3) and 24 (Wave 4) months later. At the post-intervention measurement, the intervention group reported significantly lower media violence use than did the control group, controlling for nonviolent media use and a range of demographic covariates. The intervention group also showed less normative acceptance of aggression and aggressive behavior, but these effects were limited to participants with higher baseline levels of aggression. Lower media violence use at Wave 2 predicted less physical aggression at Wave 3 for the total group and less normative acceptance of aggression among those participants who scored high on physical aggression at baseline. Effects of the intervention through lower media violence use at Wave 2 on reduced aggression and normative beliefs were still present at Wave 3, but were no longer significant at Wave 4. The findings have implications for understanding the role of violent media in the development of aggression in adolescence and for designing effective theory-based interventions.