MODIFICATION OF EXPERIMENTALLY-INDUCED AGGRESSION BY TEMPERAMENT DIMENSIONS

The present paper investigates the question of how experimentally indu ced aggression can be modified by different temperament dimensions, an d if subjects scoring high on different aspects of temperament differ with respect to responses to a serotonergic drug, since serotonin resp onses have been shown to be related to impulsivity and aggression. In a sample of 40 healthy males divided either according to the temperame nt dimension of Tempo or Lack of Impulse Control as measured by the EA SI Temperament Inventory were randomly assigned to four groups of a 2 x 2 design comprising the factors of ipsapirone/placebo and experiment al induction of aggression by a modified Master Mind game and a contro l condition. Emotional, behavioral, and hormone responses were recorde d. The major findings were that induction of aggression increased emot ional aggression in high Tempo scorers (high T) and behavioral aggress ion (punishing a putative coplayer by noise) in high scorers on Lack o f Impulse Control (high LIC). The serotonergic drug induced anger in h igh T under control conditions but reduced it upon experimental induct ion of aggression, whereas the opposite held true in high LIC. The hor mone responses (cortisol and prolactin) to the drug under control and aggression induction conditions were also different for high T and hig h LIC. Results were interpreted in terms of different receptor sensiti vities of the serotonergic and the dopaminergic system in the two temp erament groups. (C) 1998 Elsevier Science Ltd. All rights reserved.