Aggression, Coercive Action, and Anger

Kinds of Aggression

• Moyer identified eight types of aggression found in animals and humans.
  1. Predatory aggression: Attack against natural prey.
  2. Intermale aggression: Threat or attack by a male towards a strange male; $87\%$ of those arrested for murder and aggravated assault in the U.S. were males.
  3. Fear-induced aggression: Aggression when confined; humans resist confinement.
  4. Territorial aggression: Threat or attack when an intruder enters home territory.
  5. Maternal aggression: Attack or threat by a female when her young are present.
  6. Irritable aggression: Attack or destructive behavior due to frustration, pain, or stress; frustrations lead to aggression when large and unexpected.
  7. Sex-related aggression: Aggression elicited by the same stimuli that elicit sexual behavior; linked to jealousy and preserving genes.
  8. Instrumental aggression: Aggression that resulted in a reward; common in human behavior.

The Traditional Definition of Aggression

• Aggression is behavior against another person with the intention of committing harm.
• It refers to socially unacceptable behavior.
• Aggression includes intention and harm, not unintentional harm.

Research on Aggression

• Initial laboratory research tested if aggression arises from an intent to harm.
• Studies operationalized intent to harm by measuring whether participants would deliver a painful shock to another person.
• Participants delivered shocks, even when they thought the shocks would be extremely painful; they delivered more shocks to more severe or insulting research assistants.
• Individuals usually need to be provoked before retaliating.
• If physically harmed by unprovoked shocks, individuals retaliate in kind; when anonymous, they inflict more shocks than received.
• Massive retaliation may decrease or end an aggressive exchange.
• When very angry, the threat of retaliation doesn't reduce the tendency to attack.

New Concepts Regarding Aggression

• The underlying motivation for aggression is the human need for control.
• Aggressive behaviors are control behaviors often activated by anger.
• Violent criminals often lack basic social skills and use force to compensate.

A Working Definition of Aggression

• Aggression is the willingness to engage in physical and psychological acts of harm in order to control the actions of other people. This definition:
  • Incorporates psychological and physical harm.
  • Specifies the motivation is to gain control.
  • Defines aggression as a disposition.

Anger and Aggression

• Aggression is an instrumental behavior growing out of a need to control; anger is an emotion that interacts with instrumental aggression by lowering the threshold for it.
• Instrumental aggression does not involve anger; affective aggression is characterized by anger.

Measuring Human Aggression

• Self-report inventories determine if individuals engage in more acts of aggression or have greater feelings of anger and hostility.
• The Hostility Inventory predicts a wide range of aggressive behaviors.
• Buss and Perry's new inventory identified four components: physical aggression, verbal aggression, anger, and hostility.

The Biological Component of Aggression

Genetic Processes

• Twin studies have found a genetic factor for aggression.
• Impulsivity is linked to aggressive and antisocial behavior and may be mediated by serotonin levels in the brain.

Hormones and Aggression

Hormones and Male Aggression

• Testosterone is linked to aggression; studies increase or decrease testosterone levels and monitor aggression.
• Weight lifters using steroids had higher levels of hostility.
• Castration reduces the sex drive, hostility, and aggressive tendencies; testosterone injections restore aggressive tendencies.
• High testosterone and estradiol levels in blood samples are positively linked to aggression in men and negatively linked to indices in women.

Hormones and Female Aggression

• Attempts to link female aggression to high levels of testosterone or estradiol have been inconclusive.
• Female aggression may come from an imbalance of progesterone and estrogen during menstruation.
• Administration of progesterone alleviates irritability and hostility.

Androstenedione and Aggression in the Female Hyena

• Female spotted hyenas are dominant and have higher levels of androgens.
• Higher levels of androstenedione in human adolescents are related to problem behaviors.
• $20-25\%$ of aggression is due to endocrine factors.

Sex Differences in Males and Females

• Males commit more crimes, but research studies find little difference between male and female aggression.
• Males are more aggressive than females, but the difference is small.
• Men scored slightly higher on verbal aggression and hostility and much higher on physical aggression and were equal on anger.
• Women are more cautious about using physical aggression and experience more guilt and anxiety.

Neuromechanisms

Temporal Lobe Pathology

• Charles Whitman had a brain tumor in the medial part of the temporal lobe and killed many people.

Amygdala

• Lesions or ablations of the amygdala produce a calming effect.
• Psychosurgery of the temporal lobes and the amygdala reduces aggression and violence.
• The amygdala triggers the fight-or-flight hormones; it also initiates defensive actions without the full involvement of the neocortex and our ability to act impulsively.

Learned Component of Aggression

Frustration

• Frustration increases the tendency to become aggressive when goal-directed behavior is blocked.

Frustration and the Energization of Behavior

• Frustration energizes behavior; behaviors following nonreward are executed with more vigor.
• Frustration facilitates aggression when quite intense and unexpected or arbitrary in nature.

Frustration and the Direction of Behavior

• Frustrated people often do not attack the source of the frustration to avoid retaliation.
• Berkowitz suggests frustration generates aggressive inclinations to the degree that it arouses negative affect.