Aggression, Coercive Action, and Anger

Kinds of Aggression

• Moyer identified eight types of aggression, each involving different brain structures:
  1. Predatory aggression: Hunting for food or sport.
  2. Intermale aggression: Male response to a strange male; 87% of those arrested for murder and aggravated assault were males.
  3. Fear-induced aggression: Aggression when confined; humans resist confinement.
  4. Territorial aggression: Protecting home, office, or land; laws recognize the right to protect territory.
  5. Maternal aggression: Protecting offspring.
  6. Irritable aggression: Destructive behavior due to frustration, pain, deprivation, or stress; frustrations lead to aggression when large and unexpected.
  7. Sex-related aggression: Aggression due to stimuli that elicit sexual behavior; jealousy linked to preserving genes.
  8. Instrumental aggression: Aggression that resulted in reward; humans use coercive action to achieve goals.

Traditional Definition of Aggression

• Aggression is behavior against another person with the intention to committing harm.
• Aggression includes physical and socially unacceptable behavior.
• Aggression is defined by intention and can have fatal consequences.

Research on Aggression

• Early Laboratory Research:
  • Tested that aggression arises from an intent to harm.
  • Participants deliver a painful shock to another person and were provoked by means of a negative evaluation.
  • Participants deliver more shocks to research assistants who were more severe in their evaluation.
  • Individuals usually need to be provoked in some way before they will retaliate.
  • Individuals retaliate in kind and if they are anonymous, they tend to inflict more shocks than they received.
  • Massive retaliation decreases or ends an aggressive exchange.
  • When the person is very angry the threat of retaliation does not reduce the tendency to initiate an attack.

New Concepts Regarding Aggression

• The Underlying motivation for acts of aggression is the human need for control.
• Aggression is the willingness to engage in physical and psychological acts of harm in order to control the actions of other people.
• This definition retains all the essential features of the traditional definition but extends it in three important ways:
  • First, it incorporates the idea that aggression involves psychological as well as physical harm.
  • Second, it specifies that the motivation underlying aggression is to gain control over the behavior or other people.
  • Third, it defines aggression as a disposition.

Anger and Aggression

• Anger lowers the threshold for instrumental aggression.
• There is a strong positive correlation between anger and aggression, people often feel angry without becoming aggressive and often become aggressive without feeling angry.
• Useful to distinguish instrumental aggression, which does not involve anger, and affective aggression, which is characterized by anger.

Measuring Human Aggression

• Humans differ in their tendency to act aggressively.
• The Hostility Inventory developed by Buss and Darkee (1957) has been shown to predict a wide range of aggressive behaviors.
• The Aggression Inventory identified four factors:
  • physical aggression, verbal aggression which involve hurting other people, represent the instrumental component.
  • anger involves physiological arousal, represents the emotional or affective component.
  • hostility involves feelings of ill will and injustice, represents the cognitive component of aggression (Buss & Perry, 1992).

Biological Component of Aggression

• Genetic Processes:
  • Studies of twins indicate there is a strong genetic effect.
  • The temperamental trait of impulsivity is related to aggressive and antisocial behavior.
  • Increased serotonin produces response inhibition, while decreased serotonin produces hyperactivity in associated brain structures.

Hormones and Aggression

• Hormones and Male Aggression:
  • One of the main hormones linked to aggression is $testosterone$.
  • Animal studies showed that steroids increase aggressive behavior.
  • Follow-up studies of castrated sex offenders have indicated that castration reduces hostility and aggressive tendencies.
  • Decreases in testosterone result in decreased aggression.
    Hormones and Female Aggression:
  • Female aggression may come from an imbalance of progesterone and estrogen.
  • PMS, school girls break more rules, women prisoners are more likely to get into trouble during early menstruation.
  • The levels of estrogen and progesterone during a 28-day menstrual cycle are shown in Figure 8-1.

Androstenedione and Aggression in the Female Hyena

• Female spotted hyenas force their dominance over males through their size and aggression.
• Levels of testosterone and related androgens are higher in dominant female than in the average male and six times higher than in the average female.

Sex Differences in Males and Females

• Males are more aggressive than females, the difference is quite small (Eagly & Steffen, 1986).
• Men scored slightly higher on verbal aggression and hostility, much higher on physical aggression, and were equal on anger (Buss & Perry, 1992).
• Magnitude of the difference between males and females is related to their tendency to use physical harm.

Neuromechanisms

• Temporal Lobe Pathology:
  • Charles Whitman had a brain tumor, whose exact location was difficult to pinpoint, located on the medial part of the temporal lobe. He killed his wife, his mother and killed 14 people at the University of Texas administration building.

Amygdala

• Lesions or ablations of the amygdala produce a calming effect.
• Using animal research as a model, surgeons have cut away part of the temporal lobes and the amygdala.
• The amygdala triggers the body's fight-or-flight hormones, mobilizes the center for movement, activates the cardiovascular system, triggers the release of norepinephrine, and generally makes us more alert (LeDoux, 1986, 1992, 1993, 1996).

Learned Component of Aggression

• Frustration increases when goal-directed behavior is blocked.

Frustration and the Energization of Behavior

• Frustration is comparable to nonreward, which appears to energize behavior (Amsel, 1958);
• Baron (1977) has concluded that frustration can facilitate later aggression, frustration is quite intense, unexpected or arbitrary in nature.

Frustration and the Direction of Behavior

• Frustration generates aggressive inclinations to the degree that it arouses negative affect.