Individual differences in the study of human aggression

Excessive concern for simplicity has often led us to underestimate the complexity of aggression. Over the years, several scales related to aggression have been identified and validated both on adults and on children. Ultimately, two main higher order dimensions, emotional responsivity and proneness to aggression, repeatedly emerged in a series of second-order factor analysis. These dimensions are rather similar to two of the big five factors of personality: neuroticism/emotinal stability and hostility/agreeableness, respectively. Several studies corroborate the plausibility of a higher level bidimensional conceptualization of aggression that, while preserving the heuristic validity of looking for more specific constructs of aggression, can link the field of aggression to the field of personality. © 1994 Wiley-Liss, Inc.     

Legitimized aggression and sexual coercion: Individual differences in cultural spillover

Correlations between aggressive attitudes and sexual coercion have consistently been found in numerous empirical studies across social science disciplines. Extrapolating from sociological research linking indices of legitimate aggression by state to statewide frequencies of rape, we have extended the investigation of legitimate aggression and coercive sexuality to the individual level. The specific purposes of this research were to index the breadth and level of endorsement of legitimized aggression at the individual level and to measure the association between such an index and coercive sexual behavior. These purposes were achieved across the course of three studies in which we created a new dispositional measure, the Proclivity for Legitimized Aggression Questionnaire (PLAQ), and replicated a sociocultural level correlation with coercive sexual behavior (Study 1); assessed the individual differences level construct validity of the PLAQ (Study 2); and tested whether endorsement of items on the PLAQ were related to content‐relevant behaviors (Study 3). The PLAQ was internally consistent, modestly but significantly correlated with a measure of self‐reported coercive sexual behavior, and characterized by promising construct validity. Aggr. Behav. 27:26–43, 2001. © 2001 Wiley‐Liss, Inc.     

Individual differences in psychophysiological responsiveness in laboratory tests of deception

The study examined the interrelationship of a number of measures of electrodermal activity under varying degrees of task demand and their relationship to differential electrodermal responding to critical questions in either a card test (n=126) or a mock agent test (n=84) of deception. The data indicated two dimensions of electrodermal responsiveness: one, a reactivity dimension, related predominantly to differences in base level, and the other, a lability dimension, related to differences in response frequency. A third dimension reflecting differences in the extent to which the electrodermal system was the most responsive relative to other systems was not independent of the second. Both the reactivity and lability dimensions related to indices of differential responding in the laboratory tests of deception, with the second increasing the predictive power of the first. The results were interpreted in terms of two-factor theories of the orienting response relevant to the physiological detection of deception.     

Individual differences in anger and displaced aggression: The role of metacognitive beliefs and anger rumination

Metacognitive model is a theoretical approach aimed to explain emotion dysregulation and others emotion-related issues, such anger, and aggressive behavior. From this model, people having higher maladaptive metacognitive beliefs (e.g., “I can't control my thoughts”) are more likely to activate and maintain anger rumination and, in turn, to experience higher levels of anger and to act aggressively. Preliminary evidence shows the role of metacognitive beliefs on anger rumination and anger levels, whereas no studies have examined its association with aggressive behavior. This study first examined the associations between metacognitive beliefs, anger rumination, anger levels, and the propensity to engage in displaced aggression, and second, the mediation role of anger rumination in the relations among metacognitive beliefs and anger and displaced aggression. Participants were 947 students and non-students from general population recruited in two different countries (Australia and Spain). Correlational analyses revealed a similar pattern of results in the Australian and Spanish sample, with participants having dysfunctional metacognitive beliefs also showing higher anger rumination, higher levels of anger and a higher tendency to act aggressively. Structural equation analyses revealed the associations of metacognitive beliefs with anger levels and displaced aggression was fully mediated by anger rumination in both samples. These results suggest that metacognitive beliefs should be considered in comprehensive models and in the therapy of anger problems and aggression.     

Individual differences in stress and fatigue in two field studies of driving

This paper reports the findings of two field studies of Australian drivers in which individual differences in stress and fatigue were investigated. In the first study, 58 professional drivers completed measures of mood, fatigue and other subjective stress state measures, before and after performing a prolonged driving trip. The results indicated that the scales were sensitive to increased fatigue following the driving trip, and correlated appropriately with Fatigue Proneness, a driver stress trait. In the second study, 104 non-professional drivers completed identical subjective stress state measures as the professional drivers, before and after performing a driving trip. Drivers completed a measure of driving-related stress traits, the Driver Stress Inventory (DSI), and a measure of coping, the Driving Coping Questionnaire (DCQ). Both measures were predictive of state response to driving, and the association between Fatigue Proneness and post-drive fatigue found in the first study was replicated. Findings from these studies suggest that fatigue and stress reactions to driving are psychometrically distinct, but may have some common antecedents, such as use of emotion-focused coping. The studies confirm the importance of fatigue and stress as potential safety problems, but also highlight the role of individual differences in response to the demands of driving.     

Individual aggression and a violent society

The first was [a woman], 32, waiting for a bus on San Francisco's Geary Boulevard at 7:57 one evening last week. A man stepped up to her, shot her twice fatally in the chest, and ran back to a waiting dark-colored Cadillac. Ten minutes later and eight blocks away ? a retired Coast Guardsman who had turned 69 that day was struck down by three bullets in the back and belly. At 9:15, near Market Street, octogenarian ? died instantly from two bullets in his back. Three miles south, at 9:50, [a woman], 45, was cut down as she stood in the doorway of a laundromat. And ten blocks away, at 10:10, [another woman], 23, the mother of a four-month-old boy, was climbing the stairs to her new house when a man walked up and said amiably, “Hi, howya doin'?” [She] turned to reply, and a bullet burrowed through her body to her spine, possibly paralyzing her for life. (“Crime: Nothing Personal,'Newsweek February 11, 1974.)     

Sex differences in instigative aggression

The instigative aggression paradigm, in which male and female subjects instructed a female confederate which shock to set for an opponent in a competitive reaction time task, was employed. It was observed that males instigated more aggression than females and that both passive and assertive noncooperation effectively reduced instigative aggression, the assertive form of noncooperation being only slightly less effective. Questionnaire data suggested that females found the passive noncooperator most desirable while males found her least so. Results were discussed in terms of violation of task role and sex role expectations.     

Individual differences in rate of affect change: studies in affective chronometry

Three studies explored individual differences in rate of affect change. Participants watched affect-inducing videos and reported their affect twice in 20 min. Individual differences in rate of affect change emerged independently of initial affect intensity and stress appraisals, revealing 2 affect-change profiles. Positive affect augmenters (extraverts, emotionally stable participants, and those with high negative mood regulation expectancies) showed slow rates of positive and rapid rates of negative affect decay. Negative affect augmenters (introverts, neurotics, and participants with low negative mood regulation expectancies) showed slow rates of negative and rapid rates of positive affect decay. These findings expand the literature on affective style, have adaptational implications, and highlight future research directions.     

Individual differences conducive to aggression and violence: trajectories and correlates of irritability and hostile rumination through adolescence

This study examined the developmental trends of Irritability and Hostile Rumination at different times over the course of adolescence in a sample of 500 youth. Participants were 12 years old at the time of the first assessment and 20 years old at the last assessment time. Three objectives were pursued: (a) investigation of the stability and change of both Irritability and Hostile Rumination; (b) identification of developmental trajectories of Irritability and Hostile Rumination; and (c) determination of whether different trajectories of Irritability and Rumination were significantly related to physical and verbal aggression and violent conduct at age 20. Results showed that Irritability and Hostile Rumination were highly correlated and stable over time. Four developmental trajectories were identified for both dimensions. Whereas most of the participants demonstrated stable mean levels of Irritability, half of the youth either increased or decreased in their level of Hostile Rumination over time. In addition, high Irritability trajectories were associated with high physical and verbal aggression while high Hostile Rumination trajectories were associated with high levels of violent behavior.     

Individual differences in Pollyannaism

The Pollyanna Principle states that people process pleasant information more accurately and efficiently than less pleasant information. This study examined whether different measures of Pollyanna tendencies are correlated with each other. Fourteen measures of Pollyannaism were derived for 133 students. The results showed that subjects who rated themselves as optimistic or happy also showed Pollyannaism on other measures of happiness, believed that the events in their lives were pleasant, gave themselves positive ratings on personality characteristics, recalled pleasant words more often than unpleasant words, supplied more free associations to pleasant stimuli than to unpleasant stimuli, listed pleasant items first, and judged that pleasant words were more frequent in the English language.     

Conspecific aggression in the laboratory rat.

Attacks by dominant colony males of a domesticated rat strain on conspecific strangers introduced into the colony include both a full range of threat displays and actual biting attack. These dominant males attack and bite both anesthetized and unanesthetized strangers, but threat displays and bites to anesthetized rats are limited. Lesions resulting from these bites are nonrandomly distributed, with most damage to the head and upper back and very few bites to ventral surfaces. When introduced strangers were left in the colonies for several days, 66% were killed, indicating that domesticated rats are capable of lethal attacks on conspecifics without external provocation.     

Individual and sex differences in reminiscence

Inverted alphabet printing, rotary pursuit, and mirror tracking tasks were administered to 84 subjects in order to ascertain (a) reproducibility of reminiscence scores within and between tasks and (b)sex differences in reminiscence. With prerest performance levels held constant by second-order partial correlation procedures, reproducibility of individual reminiscence differences within tasks was significant but quite low, while predictability of reminiscence from one task to another was negligible. The sexes reminisced essentially alike on inverted alphabet printing, but females reminisced more than males on the other tasks, presumably because they were relatively more depressed by massed practice on these tasks. Thus, individual and sex differences were essentially task specific. Implications of results for reminiscence theories and for the credibility of alleged relationships between reminiscence and other organismic variables were discussed.