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  • Social psychologists are interested in what causes aggressive behaviour and have sought for several years to achieve a better understanding of its nature through research. They anticipate that the better we understand human nature, the better equipped we are to prevent aggressive acts.

  • Aggression comes in two forms: hostile (affective) and instrumental. Hostile aggression occurs when the primary goal of an action or behaviour is to make the victim suffer. Individuals who participate in hostile aggression, then, are simply seeking to harm or injure the target of their attack. Instrumental aggression occurs when the primary goal of the action is not to make the victim suffer but to attain a non–injurious goal. An individual who participates in instrumental aggression will harm or injure another as a way of obtaining various rewards such as control of a situation or improved self–esteem.

  • While we often think of aggression as being triggered by the actions of another person, it can also be triggered by cultural factors. A culture's system of values, beliefs, and norms may suggest that aggression is appropriate, or even necessary, in certain circumstances. In cultures where the law is weak and citizens need to protect themselves, the act or even the threat of violence is considered to be essential.


  • Freud believed that aggression stems from a self–destructive impulse and that humans must act out that impulse in order to release negative energy and return to a state of calm—a behaviour Freud refers to as a "death drive." Lorenz believed that through evolution, humans developed a fighting instinct similar to that found in animals.

  • Social learning theory suggests that human aggression is largely learned by observing the aggressive behaviour of other people and is affected by consequences such as punishment or reward in the individual's environment. Psychologist Albert Bandura developed social learning theory, also referred to as social cognitive theory, during the 1960s.

  • The General Aggression Model (GAM) builds on the social learning theory and provides a more integrative framework for specific theories of aggression by including input variables. According to the GAM, two major types of input variables can trigger events that may eventually lead to blatant aggression—factors that relate to current situations, or situational factors, and factors that relate to the individuals involved, or personal factors.


  • There are several factors that influence aggression, including aversive experiences, arousal, and cues in the environment. Aversive experiences can come in the form of pain, discomfort, or personal attacks. Arousal from sources such as exercise and sex can be transformed into aggression. Environmental cues such as guns or other weapons increase the likelihood of aggression.

  • Viewing violence either in person or on television can increase aggressive behaviour, particularly when individuals are provoked. It can also desensitize viewers to violence, making them less aware of the harmful results of their actions.


  • Aggression is not inevitable. It can be reduced and even prevented in many cases through several strategies. The source of the aggression might impact which prevention strategy is most effective in a given situation.

  • Children are likely to imitate aggressive behaviour if they see that behaviour rewarded. Similarly, they are less likely to imitate aggressive behaviour if that behaviour is punished.

  • Just as the modelling concept can lower inhibitions and encourage imitation when aggressive behaviour is observed, it can also increase self–control and encourage obedience when non–aggressive behaviour is observed.