Aggression

Some theorists argue that the foundations of aggression are biological. Biological factors that influence aggressive behavior include hormones, physiological illness, and temperament.

Hormones play some indirect role in human aggression. Interaction with external stimuli may affect the threshold of aggressive behavior. Some researchers have concluded that high testosterone levels could be a result of aggressive behavior. In women, premenstrual tension syndrome is associated with a number of aggressive behaviors, such as violent crime.

People with a serious physiological illness, such as cancer, may be affected by negative mood states. These mood states may indirectly affect the aggressive behavior of individuals.

Temperament may be indirectly related to aggressive behavior. People who are impulsive are more likely to be aggressive than people who have a deliberate temperament.