Aggression, Coercive Action, and Anger - Summary

Kinds of Aggression

• Moyer identified eight types of aggression, each involving different brain structures.
  1. Predatory aggression: Attack against natural prey.
  2. Intermale aggression: Threat or attack by a male in response to a strange male (87% of those arrested for murder and aggravated assault in the US were males).
  3. Fear-induced aggression: Aggression when confined; preceded by escape attempts.
  4. Territorial aggression: Threat or attack when an intruder is discovered on home-range territory. Homes, offices and private land are examples of territories that humans protect.
  5. Maternal aggression: Attack or threat by a female toward an intruder when her young are present.
  6. Irritable aggression: Attack or destructive behavior due to frustration, pain, deprivation, or other stressors.
  7. Sex-related aggression: Aggressive behavior elicited by sexual stimuli.
  8. Instrumental aggression: Aggressive behavior resulting in reward.

Traditional Definition of Aggression

• Aggression is defined as behavior against another person with the intention of harming them.
• It refers to socially unacceptable behavior.
• Aggression is based on intention and harm.

Research on Aggression

• Early research tested the idea that aggression arises from an intent to harm.
• Studies operationalized intent to harm by measuring whether participants would deliver a painful shock to another person.

New Concepts Regarding Aggression

• The underlying motivation for acts of aggression may be the human need for control.
• Aggression can be defined as the willingness to engage in physical and psychological acts of harm in order to control the actions of other people.

Anger and Aggression

• Aggression is an instrumental behavior arising from a need to control.
• Anger is an emotion that can interact with instrumental aggression and lower the threshold for it.
• Instrumental aggression does not involve anger.
  -Affective aggression is characterized by anger.

Measuring Human Aggression

• Researchers use self-report inventories like the Hostility Inventory to determine individual differences in aggression.
• Buss and Perry's inventory identifies four components: physical aggression, verbal aggression, anger, and hostility.

Biological Component of Aggression

Genetic Processes

• Twin studies suggest a genetic factor for aggression, but some studies do not control for the environment.
• Impulsivity, related to aggression, may be mediated by serotonin levels in the brain.

Hormones and Aggression

Hormones and Male Aggression

• Testosterone is linked to aggression, but it's uncertain whether it's a cause or effect.
• Studies on steroid users and castrated sex offenders indicate that testosterone plays a role in aggression.

Hormones and Female Aggression

• Attempts to link female aggression to testosterone or estradiol have been inconclusive.
• Imbalances of progesterone and estrogen may be a factor in female aggression.
• Studies indicate that the administration of progesterone will alleviate irritability and hostility.

Androstenedione and Aggression in the Female Hyena

• Female spotted hyenas are dominant through their size and aggression.
• Androstenedione correlates to problem behaviors in human adolescents of both sexes.

Sex Differences in Males and Females

• Males are more aggressive than females, but the difference is small.
• Women are more cautious about using physical aggression and show considerable guilt and anxiety about aggression.

Neuromechanisms

Temporal Lobe Pathology

• Temporal lobe tumors may be associated with aggression.

Amygdala

• Lesions of the amygdala have a calming effect in animals.
• Psychosurgery has had a partially effective role in reducing aggression and violence in humans.
• The amygdala triggers the body’s fight-or-flight hormones, initiates defensive actions without the involvement of the neocortex.

Learned Component of Aggression

Frustration

• Frustration increases the tendency to become aggressive when goal-directed behavior is blocked.
• Frustration can energize behavior, but not all frustrated behaviors lead to aggression.