have aggression. We as a species have a history of intentionally inflicting physical or psychological harm
to others. Take a moment, and think about how many people have been killed by other humans in wars, and even in times of peace. It is tens of millions!
According to the Federal Bureau of Investigation, in 1999, some alarming statistics:
Where Aggression Occurs
Aggression and violence can be found anywhere there are people. The home, the workplace, schools, and on the road to name a few.
Causes of Aggression
Instinct theory was one of the earliest theories of the cause of aggression. The theory says that human beings, as well as other animal species, are genetically programmed for such behavior. The infamous Freud believed that humans have an aggressive instinct toward inward as self-destructive and outward as aggression or violence toward others. Konrad Lorenz, a Nobel Prize winner, claimed that aggression springs from an inborn fighting instinct common in many animal species. However, most social psychologists consider human behavior too complex to attribute to instincts.
Biological Factors in Aggression
Although most psychologists reject the instinct theory, they do concede that biological factors are involved. Low arousal level of the autonomic nervous system is a biological factor that is very closely related to aggression. By low arousal level it is meant low heart rate and lower reactivity. It has been linked to antisocial and violent behavior. People with low arousal levels tend to seek stimulation and excitement and often exhibit fearlessness, even in the face of danger.
It has been scientifically proven that men are more physically aggressive than women, in general. The male hormone testosterone is involved. As a matter of fact, the primary biological variable related to domestic violence (which is including both verbal and physical abuse) appears to be high testosterone levels, which are highly heritable. A correlation between high testosterone levels and aggressive behavior has been found. Testosterone levels in both male and female college students to be positively correlated with aggression and negatively correlated with prosocial behavior. However, abnormally low levels of testosterone have also been linked to aggression. Violent behavior has also been linked to low levels of serotonin.
Brain damage, brain tumors, and temporal lobe epilepsy have all been related to aggressive and violent behavior. Alcohol is also often a factor in aggression. Alcohol and other drugs that affect the brain’s prefrontal cortex lead to aggressive behavior in humans as well as in other animals by disrupting normal executive functions.
The frustration-aggression hypothesis suggests that frustration produces aggression. Frustration does not always cause aggression but it is especially likely to if it is intense and seems to be unjustified. Aggression in response to frustration is not always aimed at the people causing it. The aggression may be displaced if the preferred target is too threatening or not available.
The social learning theory of aggression says that people learn to behave aggressively by observing aggressive models and by having their aggressive responses reinforced. Aggression is known to be higher in groups and subcultures that condone violent behavior and accord high status to aggressive members.