Exogenous Testosterone Rapidly Increases Aggressive Behavior in Dominant and Impulsive Men.

Area of Science:

• Neuroendocrinology
• Behavioral Science
• Psychology

Background:

• Traditional views link testosterone (T) to aggression, but research is inconsistent.
• Recent studies show T potentiates brain responses to anger cues in specific regions.
• These brain areas (amygdala, hypothalamus) are rich in androgen receptors and involved in aggression.

Purpose of the Study:

• To investigate if acute testosterone administration increases aggressive behavior in men.
• To examine if personality traits (dominance, self-control) moderate T's effects on aggression.

Main Methods:

• A double-blind, placebo-controlled study with 121 healthy adult men.
• Participants received either testosterone (T) or a placebo.
• Aggressive behavior was measured using a decision-making game involving social provocation.

Main Results:

• Testosterone (T) alone did not significantly alter aggressive behavior.
• T's impact on aggression was contingent on personality traits.
• T increased aggression in men high in trait dominance or low in trait self-control.

Conclusions:

• This study provides the first evidence that testosterone can rapidly (within 60 minutes) enhance aggressive behavior.
• The effect of testosterone on aggression is specific to individuals with dominant or impulsive personality styles.