Title: The Roles of Executive Function, Impulsivity, and Reactivity in Aggression
Name: Peter Hoaken
Year: 2000
Type: Dissertation Fellowship

A large body of research has documented a relation between a constellation of complex cognitive abilities referred to as the "executive cognitive functions" (ECF) human aggressive behavior. A predominant theory had proposed that individuals with poor ECF are more aggressive because they are unable to inhibit impulsive behaviors. However, evidence for this relationship was typically indirect, and so this study was intended to directly assess this theory. In this study, forty-six healthy men and women completed measures of ECF, the Taylor Aggression Paradigm (TAP), which is a laboratory-based measure of human aggression, and the Go/No-Go discrimination task, a behavioral measure of impulsivity. Also, "impulsiveness" of participant responses, during the aggression, task was directly assessed by measuring latency of responses to provocation – that is, the amount of time it took them to respond after being provoked ("set-time"). It was hypothesized that men and women with sub-average ECF would perform more aggressively and more impulsively than above-average peers. Consistent with expectations, results indicated that ECF was related to aggression, and to impulsivity on the Go/No-Go task. However, low ECF men and women did not have shorter "set-times"; in fact, on this task low ECF participant's behavioral decisions appeared slightly slower than the high ECF participants. This result appears to draw into question the accuracy of the so-called "impulsivity hypothesis". This study was published in the journal Aggressive Behavior.

Recent models have proposed several pharmacological means by which alcohol may produce heightened aggression, among them that alcohol may both hyper-arouse the "reward" system and diminish the "anxiety" system. The current study examined these hypotheses, employing heart rate and blood pressure as physiological indicators of arousal, examining whether arousal differed by alcohol group, and if this related to level of aggression. Thirty-two male and 32 female participants competed on the Taylor Aggression Paradigm. The gender groups were further split into half sober, half intoxicated. Arousal was measured at baseline, post beverage consumption, and post-aggression paradigm. Participants in the alcohol condition initially demonstrated slight heart rate elevations and blood pressure decreases, but showed little arousal in response to the aggression paradigm, while sober participants demonstrated considerable arousal on both indices. Intoxicated participants were more aggressive than sober controls; men and women did not differ significantly. Regression analyses demonstrated that change in systolic blood pressure from post-beverage consumption to post-aggression paradigm acts as a mediating variable in the alcohol-aggression relationship. That is, the extent to which alcohol diminishes an individual's bodily arousal seems to be related to the likelihood that he or she will act aggressively when provoked. This study was published in Alcohol & Alcoholism.

The work I conducted while supported by the Harry Frank Guggenheim Dissertation Fellowship has allowed me to continue to develop my model of human aggression; that is, who acts aggressively, due to what characteristics, and under what conditions.