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What is aggression?
Aggression has been defined as physical or verbal behavior intended to hurt someone.
What are some theories of aggression?
Instinct theory as put forth by Freud and Lorenz, posited that aggression was a natural adaptive human instinct. Evolutionary psychologists have noted that aggression was a strategy for gaining resources, eliminating rivals, and improving ones chances of genetic survival ((Buss and Shackleford, 1997)).
Arousal of the amygdala can cause increased aggression in humans. In a human experiment in which a woman's amygdala was electrically stimulated she threw a guitar at her psychologist in a fit of rage ((Moyer, 1976, 1983)).
The prefrontal cortex acts as an inhibitory mechanism. It is responsible for constrained and appropriate behavior in social situations. It has been found that the prefrontal cortex in individuals with antisocial behavior is 15 percent smaller than those without, which may be responsible for their abnormally aggressive behavior.
Animals can be bred to be aggressive which shows that there may be some genetic component. It has also been found that a person's temperament usually endures throughout their life ((Larsen & Diener, 1986)).
Testosterone has been shown to be linked with aggressive behavior. After the age of 25, both testosterone levels and acts of violent crimes decrease greatly.
Alcohol has been shown to increase aggression especially when provoked. Alcohol disinhibits an individual. This can be compared to the long-term disinhibition that occurs in individuals with antisocial behavior due to an underdeveloped prefrontal cortex. Over half of all acts of rape occur while the aggressor is under the influence of alcohol.
What causes Aggression?
- Frustration-Aggression Hypothesis ((Dobbs et.al., 1939))
- Aggression is supposedly always preceded by some kind of frustration
- Today aggression is seen as caused by many factors, not just frustration (although it may still play a part in causing aggression)
- Aggressive Drive Hypothesis
- Frustration causes a drive state, which motivates behaviors in the same way as other primary drives such as hunger, thirst, etc.
- Intervening variables
- Fear of Retaliation
- Displaced aggression to a more available target
- Physical arousal may include, but is not limited to, sexual arousal
- Viewing violence may facilitate aggression by eliciting increased autonomic arousal
- Since sexual material also elicits arousal, sexual arousal can be misattributed as aggressive arousal
- Excitation Transfer Theory: previously provoked subjects were more aggressive after being physically aroused (whether by running on a treadmill or viewing porn, etc.) because arousal was incorrectly attributed to be due to the provocation rather than the running/pornographic material.
- Donnerstein study: porn leads to violence against women when the film includes both sex and violence instead of just sex.
- Cognition can facilitate or inhibit aggressive responding
- Arousal may combine with cognition to create a state of heightened anger which leads to aggression
- Violent Scripts Theory: scripts are a sequence that guides our behavior in social situations; when aggression-related scripts are activated, aggression is more likely to occur
- Priming: Aggressive cues prime aggressive thoughts, memories, etc. through spreading activation, which may lead to ambiguous situations being interpreted as hostile
- Some researchers view anger as the cause of aggression
- Others think it is a parallel process, but not necessary for aggression
- Anger can also be misattributed according to Excitation Transfer Theory
- Frustration may produce anger and aggression
- What is the nature of anger?
- It could be a perceptual-motor reaction
- Or a social construction (e.g. socially-determined scripts that we follow when angry)
- It can be caused by cognitive appraisals (intent, malice, etc.)
- Increased temperature has been shown to facilitate acts of aggression
- In hot environments such as Phoenix, Arizona, drivers without air-conditioning were more likely to honk their horns than those with
- A study done on the temperature of baseball games and number of hit batsmen showed that in game above 90 degrees Fahrenheit, the batters were more likely to be hit than those in games below 80 degrees ((Reifman & others, 1991))
- Riots from 1967-1971 in 79 U.S. cities were more likely to occur on hot days as opposed to cold
- Hotter seasons of the year are correlated with an increase in violent crimes ((Anderson & Anderson, 1998, 2000))
It has been postulated that pent up emotions can fester inside of a person eventually leading the individual to burst out emotionally which can come at an inopportune time. Thus, encouraging individuals to release their emotions may seem beneficial. Quite the contrary has been found in relation to aggression. Aggression caused from sexual arousal tends to increase as sexual arousal increases. Viewing violent acts in person or on television also increases violent behavior ((Arms & others, 1979; Russell, 1983)). Nations that go to war also see an increase in homicides after the war is over ((Archer & Gartner, 1976)). Instead, it has been found that doing nothing at all can be more effective in reducing aggression than doing something in order to "blow off steam" ((Bushman, 2002)).
Encouraging positive acts as opposed to punishing negative acts can be seen as a more effective way to prevent aggression. Physical punishment of aggression can be seen as hypocritical because it is an aggressive act being used in order to prevent or deter an aggressive act. Ignoring aggressive behavior and rewarding nonaggressive behavior in children is more effective in decreasing aggressive acts than by just punishing aggressive acts alone ((Hamblin & others, 1969)).