An aggression machine. II. Interindividual differences in the aggressive defence responses aroused by varying stimulus conditions.

Abstract

PitkÄnen, L. An aggression machine. II. Interindividual differences in the aggressive defence responses aroused by varying stimulus conditions. Scand. J. Psychol., 1973, 14, 65–74.‐The subjects, six aggressive and nonaggressive groups of ten 9‐year old boys, selected by rating method, were tested with an “aggression machine” (PAM) constructed by the writer. The varying stimulus conditions included two situations of impulsive aggression and six variations of specified attackers. The results showed that (1) the larger part of the variance of the intensity of aggression in the PAM was accounted for by the situational variations than by interindividual differences in coping with thwarting situations as measured by a rating method. (2) The overtly aggressive boys showed strong discrimination between the situations, while the overtly nonaggressive boys were quite insensitive to situational variations. (3) The intensity of aggressive defence towards a boy of the same age correlated most highly with rated aggressiveness. (4) The latency, duration, and number of aggressive responses did not vary as easily as the intensity according to situations.