Aggression is the term for any act that is intended to cause pain, suffering, or damage to another person.

Aggressive driving and road rage symptoms

SOURCE: Washington State Patrol.

Theories about the nature and causes of aggression vary widely. Those with a biological orientation are based on the idea that aggression is an innate human instinct or drive. Sigmund Freud explained aggression in terms of a death wish or instinct that is turned outward toward others in a process called displacement. Aggressive impulses that are not channeled toward a specific person or group may be expressed indirectly through safe, socially acceptable activities such as sports or a psychoanalytic process called catharsis that helps to clear the aggressive attitude or behavior. Biological theories of aggression have been advanced by ethologists, researchers who study the behavior of animals in their natural environments. Several have advanced views about aggression in humans based on their observations of animal behavior. The aggressive instinct postulated by these scholars builds up spontaneously—with or without outside provocation—until it is discharged with minimal or no provocation from outside stimuli. However, instinct theories of aggression have been largely discredited, and other explanations are more popular.

A frustration-aggression theory introduced in the 1930s proposed that aggression is a response to the frustration of certain goal-directed behavior by an outside source rather than occurring spontaneously and for no reason. The goals may include such basic needs as food, water, sleep, sex, love, and recognition. Contributions to frustration-aggression research in the 1960s established that an environmental stimulus must produce not just frustration but anger in order for aggression to follow and that the anger can be the result of stimuli other than frustrating situations (such as verbal abuse).

In contrast to instinct theories, social learning theory focuses on aggression as a learned behavior. This approach stresses the roles that social influences, such as role models and reinforcement, play in the acquisition of aggressive behavior. The work of Albert Bandura, a prominent researcher in the area of social learning, demonstrated that aggressive behavior is learned through a combination of modeling and reinforcement. Children are influenced by observing aggressive behavior in their parents and peers and in cultural forms such as movies, television, and comic books. While research has shown that the behavior of live role models has a more powerful effect than that of characters in movies, television, and video games, such media still exert strong influences on behavior. The International Society for Research on Aggression issued a report in 2012 stating that no single risk factor causes a child or adolescent to act aggressively. Instead, research shows that the accumulation of risk factors leads to aggressive acts, and each factor increases the likelihood of aggression, especially when some form of provocation is involved.

Quantitative studies have found that network television averages 10 violent acts per hour, and onscreen deaths in movies such as Robocop and Die Hard range from 80 to 264. Some behavior experts argue that this type of violence does not cause violence in society and may even have a beneficial cathartic effect. However, correlations have been found between the viewing of violence and increased interpersonal aggression, both in childhood and in adolescence. Media characters make attractive role models, and often their on-screen actions are presented as socially acceptable and justified. This reward for violent behavior may be seen as enjoyable, which may result in an association between aggression and positive feelings. In addition to its modeling function, viewing violence can lead to aggressive behavior by increasing viewers’ arousal, desensitizing viewers to violence, reducing restraints on aggressive behavior, and distorting views about conflict resolution.


In psychology, the process of releasing strong or repressed emotions and deriving relief from this process.
In Freudian psychology, an unconscious defense mechanism in which the mind substitutes emotions, ideas, or wishes to prevent experiencing anxiety when aggressive or sexual impulses are being felt.
Exhibiting behavior that may be imitated by another person, especially children or adolescents to learn a specific skill or to develop certain social skills.
Actions or words that are deliberately intended to make a person or persons annoyed or angry or to encourage a response of some kind.
An obsessive desire to setthings on fire, often considered an act of violence against others.

The findings of social learning theory address not only the acquisition, but also the instigation, of aggression. Once an individual has learned aggressive behavior, which specific environmental circumstances will activate it? The most obvious are adverse events, including frustration of desires and verbal and physical assaults. Modeling, which is important in the learning of aggression, can also play a role in instigating aggression. Seeing other people act in an aggressive manner, especially if they are not punished, can remove inhibitions against acting aggressively oneself. Modeled aggression may serve as a source of emotional stimulus. If the modeled behavior is rewarded, the reward may then act vicariously as an incentive for aggression in the observer.

Aggression motivated by reward can become a means of obtaining what one wants. Another motive for aggression is, paradoxically, obedience. Many violent acts have been committed in both military and civilian life at the bidding of another person. Other possible motivating factors are stressors in the physical environment, including crowds, noise, and temperature, as well as delusions resulting from mental illness. In addition to the acquisition and instigation of aggression, various types of reinforcement, both direct and vicarious, help determine whether aggression is maintained or discontinued.

Researchers have attempted to learn whether certain childhood characteristics are predictors of aggression in adults. Traits found to have connections with aggressive behavior in adulthood include maternal deprivation, lack of identification with one's father, pyromania, cruelty to animals, and parental abuse. A longitudinal study found that patterns of aggression were established by the age of eight; the aggressive behavior of both boys and girls at this age was a strong predictor of their future aggression as adults. Other factors cited in the same study are the father's upward social mobility, the child's degree of identification with parents, and early preference for violent television programs. Although video games and movies were not included in the longitudinal study, the International Society for Research on Aggression reported in 2011 that preference for violence is evident in these entertainment media as well.



Freedman, Jonathan L. Media Violence and Its Effect on Aggression. New York: Oxford University Press, 2002.

Green, Russell G. Human Aggression. Philadelphia: Open University Press, 2001.

Kazdin, Alan E. Parent Management Training: Treatment for Oppositional, Aggressive, and Antisocial Behavior in Children and Adolescents. New York: Oxford University Press, 2005.

Pepler Debra J., and Kirstan C. Madson. The Development and Treatment of Girlhood Aggression. Mahwah, NJ: Lawrence Erlbaum Associates, 2005.


Ballargian R. H., et al. “Gender Differences in Physical Aggression: A Prospective Population-based Survey of Children Before and After 2 Years of Age.” Develop-mental Psychology 43, no. 1 (January 2007): 13–26.

Escobar-Chavez, Liliana, and Craig A. Anderson. “Media and Risky Behaviors.” The Future of Children 18, no. 1 (spring 2008): 147–80.

Media Violence Commission. “Report of the Media Violence Commission.” International Society for Research on Aggression 38, no. 5 (September/October 2012): 335–41.


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