A direct assessment of the role of state and trait negative emotion in aggressive behavior

The purpose of the current study involved an attempt to elucidate the effects of negative emotional activation on aggressive responding within a laboratory aggression paradigm. Individual differences in the emotional priming of aggression were investigated by choosing participants who scored low and high (lower and upper quintiles, respectively) on the Multidimensional Personality Questionnaire Negative Emotionality (NEM) dimension, a measure of dispositional stress reaction, alienation, and hostility.; An adaptation of the Buss Aggression Machine paradigm, wherein participants were asked to "supervise" another student (actually a confederate of the experimenter) who was purportedly engaged in a digit span task, was utilized. When the confederate made an incorrect response, the participant provided feedback by pressing one of 10 "shock" buttons. The intensity and duration of shocks delivered and the speed of aggressive responses (response latency) were recorded during the experiment. Using a within-subjects procedure, participants were exposed on some blocks (Aversive; AV) to unwarned, percussive blasts of air directed toward the larynx and not exposed to these blasts on other blocks (Non-Aversive; NAV). Moreover, an on-line psychophysiological measure of emotion, the startle probe methodology, was utilized as a physiological index of negative affect. Phasic negative emotional reactivity to the AV Blocks compared to the NAV Blocks (startle potentiation) and overall negative state during the experiment compared to baseline (startle sensitization) were both gauged to investigate the impact of phasic vs. tonic emotion on defensive behaviors. Predictions involved a NEM Group (High vs. Low) X Block Type (AV vs. NAV) interaction for shock intensity.; The hypothesis that manipulation of phasic reactivity would impact aggressive responding was supported for the response latency measure. Participants delivered shocks more quickly during the AV compared to the NAV Blocks. As for shock intensity, the primary measure of aggression, the affect manipulation did not produce phasic differences in aggressive responding. Instead, the High NEM group compared to the Low NEM group initially (during the first block) delivered higher shock intensities during AV compared to NAV Blocks; however, in subsequent blocks, only a NEM Group effect (High NEM > Low NEM) emerged for shock intensity. In addition, although both groups responded to the stress manipulation with equivalent phasic reactivity (startle potentiation), High NEM individuals exhibited greater tonic anxiety (startle sensitization) to the experimental procedures relative to baseline startle reactivity. These data, along with the correlations between startle sensitization and aggressive measures, suggest that it is not phasic negative emotional activation (fear) that potentiates overt aggression (i.e., shock intensity), but rather the presence/development of a tonic negative affective state, primarily in persons predisposed to emotional reactivity. These results also have implications for the analysis of how different facets of aggressive response (intensity, duration, response latency) may be differentially related to different forms of emotional activation (phasic vs. tonic responsivity).