The Effects of Individual and Context on Aggression in Repeated Social Interaction

In two studies using variations of the Prisoner’s Dilemma game, we explore the combined impact of individual traits and social context on aggressive behavior. In the first study, we compared defection rates in the Iterated Prisoner’s Dilemma when participants were presented with a payoff matrix (Description condition) or learned payoffs through experience (Experience condition). Interpersonal trust and maximizing tendency led to relatively more cooperation in the Description condition than in the Experience condition, demonstrating that individual characteristics manifest differently depending on the information available to decision-makers. In the second study, we employed a new game paradigm, the Intergroup Prisoner’s Dilemma with Intragroup Power Dynamics, to examine the way that power motives influence extreme aggressive behavior. We discovered that certain individuals exhibit very high levels of defection, but only when they play with particular combinations of predefined strategies, suggesting further how the confluence of individual factors and context can induce aggression.