Aggressive Behavior

Aggressive individuals have a tendency to start fights, use weapons, be cruel to people or animals, steal or force sexual acts. There is a long-standing debate in the scientific community over whether aggressive behavior is mainly a result of nature or nurture. Most lean toward saying that both factors play a role. As aggressive behavior can have long-lasting psychological consequences for the victims involved, scientists strongly recommend taking all possible steps to try to prevent it.

Identification

According to University of Michigan psychologist Rowell Huesmann, aggressive behavior must be distinguished from violent behavior. Reckless driving that accidentally results in a violent car crash is violent behavior but not aggressive behavior, he says. Aggressive behaviors are "behaviors by one individual that are intended to injure or irritate another individual." Assertive actions that are called "aggressive," such as "aggressive" sales methods, often are not forms of aggressive behavior because they are not intended to injure or irritate another individual, says Huesmann. Verbal and emotional abuse, in contrast, often fit into the category.

Social Causes

Media violence is among the potential causes of aggressive behavior, says State University of New York psychologist Steven Kirsh. However, it is difficult to get solid data on this because media violence rarely produces aggression right after consumption, says Kirsh. Peer rejection is easier to study because the effects are more immediate. San Diego psychologist Jean Twenge led a 2001 study in which game losers could blast winners with an unpleasant noise. Losing participants subjected to peer rejection chose a greater intensity and duration of the noise than control subjects, reports Twenge.

Neurological Causes

Abnormally low stress levels can contribute to aggression. Chicago psychiatrist Keith McBurnett found that stress hormone levels were inversely related to severity of conduct disorder in aggressive boys. Aggressive people act out in part because they are not afraid of what might happen when they misbehave, he says. A brain dysfunction that associates harming others with pleasure is another potential contributor. This finding came from a study published in the February 2009 issue of "Biological Psychology." Aggressive adolescents watching video clips of people enduring pain showed an increased activity in the ventral striatum, a center crucial for reward and pleasure, the scientists reported.

Effects

Dan Olweus, an expert in bully/victim problems at Clemson University and the first to conduct a scientific study on the subject, points out that the victims of bullies and other aggressive individuals can have long-lasting personality problems as adults. In his studies, Olweus found that victims often suffer from depression and low self-esteem later in life. The dominant peers shaped the negative elements of the victims' personality. By being constantly bullied, the victims slowly accepted the bullies' views of them as truths, reports Olweus.

Prevention/Solution

Olweus was the founder of a bullying prevention program that has been implemented in schools around the world. The program involves adapting school-wide rules against bullying, instating consequences and developing supervision systems. Schools that implemented the program have seen a 50 percent reduction in aggression incidents, reports Olweus. As a preventive measure against aggression incidents from violent entertainment, the United States requires warning labels on violent movies and video games. But the labels don't always have the intended effect, says Kirsh. Entertainment marked "violent" has a forbidden fruit effect--the warnings increase the attractiveness of the products, he adds.