Chp 9: Hormones and Aggressive Behavior
How do we define aggressive behavior?
What role do hormones play in aggression? (animal studies)
- gonadal steroids regulate the frequency and timing of aggressive responses
- in males: testosterone stimulates social aggression--competitive responses
- in females: 1) progesterone acts to inhibit aggressive behavior--important for display of sex behavior, 2) prolonged exposure to estrogen and progesterone followed by estrogen alone facilitates the display of maternal aggression, 3) estrogen (and possibly testosterone) act to maintain “normal” levels of aggressive behavior (species differences)
- in most species, aggression is a sexually dimorphic response (males > females); androgens act to organize the brain so that gonadal steroids can activate behavior in the adult
Aggressive behavior can occur when gonadal steroids are low or absent--aggressive responses associated with predation, fear, defense.
In humans, gonadal steroids are also linked to “competitive responses”; deviant behavior (e.g., crime) most likely reflects an interaction among several variables.