Contrasting effects of a hot and a cool system in anger regulation on cooperative behaviours.

Angry mood and aggression are strongly associated. However, it is not socially acceptable to express strong aggression. Non-cooperative behaviours might be another aspect of aggressive behaviour. The present study examines the expression of non-cooperative behaviours after angry mood induction. Eighty-five university students were randomly assigned to hot or cool focus recall of a past angry event. At baseline, trait aggression and rejection sensitivity were evaluated. Just before the recall task, participants' state of angry mood was measured by the Anger Mood Scale. Then they engaged in either hot or cool focus recall of a past rejection event. Immediately after the mood induction, angry mood was measured again. They were then instructed to play the Mixed Motive game with an unknown person. Participants in both groups became angrier after the mood induction. One-way analysis of covariance, controlling for trait anger and rejection sensitivity, showed that the hot-focus participants gave significantly fewer points to the other person than the cool-focus participants. Participants high on trait aggression sent more verbally aggressive messages. The findings suggest that non-cooperative behaviour is another form of anger related aggression and might be more socially important than overt aggression.