Aggressive disposition,alcohol, and aggression

This study investigated the effect of aggressive disposition on intoxicated and non-intoxicated aggressive behavior. Prior aggressiveness was measured with a structured questionnaire. Based on a bipartite split of scores, 28 subjects were assigned to the high aggressor group, and 29 to the low aggressor group. Subjects in both disposition groups were then randomly assigned to either a drunk or sober condition, and participated in a competitive reaction time task involving the administering and receiving of electric shocks to/from a fictitious opponent under conditions of high and low provocation. Aggression was defined as shock level intensity delivered to the sham opponent. When highly provoked, sober high aggressors were significantly more aggressive than low aggressors, thus validating the measure of aggressive disposition. When intoxicated, highly provoked individuals in both the high and low aggressive disposition groups attained equal levels of aggression. It was low aggressors who responded to escalated provocation with a significant increase in aggression responding when intoxicated. These results lend support to the notion that a pharmacological effect of alcohol can increase aggressive behaviour. Aggr. Behav. 23:11–18, 1997. © 1997 Wiley-Liss, Inc.     

The moderating effect of trigger intensity on triggered displaced aggression

Many instances of aggression result in excessive retaliation in response to a seemingly trivial triggering event. The triggered displaced aggression paradigm (TDA; Miller, Pedersen, Earleywine, & Pollock, 2003) provides an experimental vehicle for exploring such occurrences. Participants were either provoked or not and were subsequently exposed to a neutral, mild, or moderately strong triggering event from a second bogus participant. Consistent with TDA theory (Miller et al., 2003), disjunctively escalated aggressive behavior occurred only among previously provoked participants when responding to the mild triggering event, but not the moderately strong or neutral trigger. Independent of provocation, the neutral triggering event elicited very low levels of aggression, whereas the moderately strong trigger elicited moderate levels of aggression. Implications for instances of real world aggression are discussed.     

The effects of alcohol and the salience of aggressive cues on triggered displaced aggression

Alcohol increases the aggression-augmenting effects of provocation. Theories of alcohol and aggression suggest that impaired cognitive processing induced by acute intoxication leads individuals to process aggression-inducing social cues differently depending on whether they are high or low in salience. We examined the effects of intoxication and aggressive cue salience within the triggered displaced aggression paradigm. An ethnically diverse sample of 74 primarily young adult participants (40 men and 34 women; M=23.28, SD=3.14 years) were recruited from the university community and surrounding area. All participants were provoked by an experimenter, randomly assigned to a 2 (alcohol condition: alcohol vs. placebo) x 2 (trigger salience: high vs. low salience) between-subjects design, and then given the opportunity to aggress against the undeserving triggering agent. As expected, intoxication combined with a salient triggering cue elicited the most displaced aggression among all conditions. These results provide the first evidence that the effect of alcohol on triggered displaced aggression is moderated by the salience of the triggering event.     

Effects of psychopathy traits on unprovoked aggression

Research has demonstrated that risk of violent behavior is high in individuals who display psychopathic traits. However, prediction of general aggression, and in particular unprovoked aggression, in nonforensic men who possess such traits has received little experimental attention to date. This study examined the role of psychopathic traits in the prediction of unprovoked aggression in a nonforensic sample. One hundred and five men completed the Levenson Self-Report Psychopathy Scales and competed in a sham aggression paradigm. These men were identified as unprovoked aggressors, provoked aggressors, and provoked nonaggressors contingent on their responses to the experimental paradigm. Findings indicated that men with high levels of psychopathic traits had a 30% greater probability of becoming aggressive in the absence of provocation relative to those with lower psychopathic traits. Results also indicated that unprovoked aggressors evinced more general aggression when provocation was initiated. Findings are discussed in terms of the importance of trait-based risk factors in the prediction of seemingly random, unprovoked aggression.     

The Effects of Acute Alcohol Intoxication and Self-Focused Rumination on Triggered Displaced Aggression

An experiment simultaneously examined the effects of acute alcohol intoxication and self-focused rumination on triggered displaced aggression. An ethnically diverse sample of 97 young adult participants (41 men, 56 women) were recruited from a university community and surrounding area. Participants were provoked by an experimenter, randomly assigned to a 2 (alcohol, sober)?×?2 (rumination, distraction)?×?2 (trigger, no trigger) between-participants design, and then given an opportunity to aggress against an undeserving other who was either completely innocent or slightly annoying. Self-focused rumination increased displaced aggression only when participants were triggered by the slightly annoying participant. Alcohol independently augmented aggression.     

Instigation to aggress and escalation of aggression examined from a personological perspective: The role of irritability and of emotional susceptibility

Two studies were conducted using Buss hostility machine paradigm to investigate the role of individual differences in irritability and emotional susceptibility on the instigation to aggress by a self-esteem lowering manipulation and on the hypothesized escalation of aggression over trials. The role of sex was also examined. In the first study, 60 highly irritable and 60 low irritable subjects were given the opportunity to deliver electric shocks to an experimental confederate, half after being provoked by a negative judgement on their performance in a learning task, half without such an experience. Each group of subjects was divided equally between males and females. It was found that highly irritable subjects, both males and females, delivered higher shocks after provocation than low irritable subjects under similar circumstances. An upward drift of shock level over trials was found only in provoked males and only in highly irritable females. In the second study, 60 highly emotionally susceptible and 60 low emotionally susceptible males and females were given the opportunity to deliver electric shocks to an experimental confederate, half after experiencing provocation, half without such an experience. It was found that provoked subjects delivered higher shocks than unprovoked subjects and that highly emotionally susceptible subjects delivered higher shocks than low emotionally susceptible subjects. Whereas an upward drift of shock levels over trials was found only in provoked males, the same effect was found in females, whether provoked or not. These findings are discussed in terms of the importance of stable personality characteristics that may mediate aggressive response.     

The effects of alcohol and delta-9-tetrahydrocannabinol on human physical aggression

Forty male undergraduates were provoked following their ingestion of high or low doses of either alcohol or delta-9-tetrahydrocannabinol (THC). The expression of physical aggression was related to the quantity of alcohol ingested. The high dose of alcohol instigated more intense aggression than the low dose. The high dose of THC, on the other hand, did not increase aggressive behavior. In fact, it tended to produce a weak suppression effect.     

Genetic analysis of “Spontaneous” intermale aggression in mice

“Spontaneous” intermale aggression was investigated in seven inbred strains of mice. A positive interstrain correlation and cross-correlation was found for two indices of fighting intensity, ie, accumulated attacking time and number of attacks. The strain aggressiveness level (percent of mice fighting in each strain) does not correlate with the intensity of aggressive behavior. It has been shown by using a genetical analysis performed on C57BL/6 and BALB/c strains, their reciprocal F₁ hybrids, and back-crosses that these indices of intermale aggression are under different genetic control. Aggressive behavior intensity depends on the additive effects of genes. The control of strain aggressiveness level revealed that a high level of aggressiveness was dominant. No reciprocal effects were found. The level of aggressiveness and the intensity of fighting seem to represent different aspects of aggression and may be controlled by different genetic mechanisms.     

The control of alcohol-related aggression: Redirecting the inebriate's attention to socially appropriate conduct

Forty male undergraduates ingested either a high dose of alcohol or a placebo, and were either provided with a nonaggressive norm or not, prior to being provoked by an opponent during a competitive reaction time task. Aggression was assessed by the intensity of shocks administered by the subject to the bogus opponent. Results suggest that the provision of an explicit nonaggressive norm enabled highly intoxicated subjects to moderate their aggressive responding even in a highly competitive situation. These findings are discussed in terms of current cognitive disruption models of alcohol-related aggression which assume intoxicated persons are unable to process information concerning appropriate standards of conduct.     

Effects of alcohol intoxication and aggressivity on aggressive verbalizations during anger arousal

We examined the moderating effect of dispositional aggressivity on the relationship between alcohol intoxication and aggressive verbalizations. Using a laboratory anger-induction task that simulated an interpersonal conflict as a method to assess aggressive verbalizations (the articulated thoughts in simulated situations paradigm), 70 participants (33 women, 37 men) consumed either an alcoholic or a placebo beverage, and then imagined a series of audiorecorded interpersonal scenarios. Two blind-to-condition raters assessed the frequency of participants' aggressive verbalizations (insults, aggressive threats, belligerent provocations) articulated during anger arousal. Aggressivity was assessed using a standard measure of dispositional aggression. Results supported the aggressivity moderation hypothesis: intoxicated participants high in aggressivity responded with significantly more aggressive verbalizations relative to low-aggressivity participants regardless of beverage condition, and three times more aggressive verbalizations relative to the high-aggressivity/placebo group. There were no gender effects. These data support the hypothesis that alcohol potentiates aggression primarily among individuals at dispositional risk for engaging in such a behavior. Aggr. Behav. 34:428-436, 2008. (c) 2008 Wiley-Liss, Inc.     

Serum testosterone,cortisol, glucose,and ethanol in males arrested for spouse abuse

Concentrations of ethanol, testosterone, cortisol, and glucose were determined in serum obtained from 16 males taken into police custody after incidents of spouse abuse. The mean blood ethanol level at the time of arrest was 33.3 ± 2.6 mM. Serum testosterone levels were significantly lower and cortisol levels higher at the time of police intervention (within 1 hour of the incident) compared to control data collected later from the subjects when sober. Offenders did not differ from a group of nonviolent pub patrons at similar blood ethanol levels (35.9 ± 4.5 mM) with respect to serum testosterone, cortisol, or glucose, but their sober state cortisol and glucose concentrations were significantly higher compared to a control group of nonalcoholic men. Intoxication or acute hormonal changes were thus not specifically associated with violent behaviour. Provocative cues, however, may have been more frequent in the offender families, as Straus Conflict Tactics data showed that offenders and victims resorted to verbal aggression significantly more often than control families. The significantly elevated cortisol and glucose concentrations in offenders when sober compared to nonviolent controls could be viewed as direct effects of life stress, or as indirect effects of stress mediated by learned escape drinking. Excessive drinking as well as spouse abuse could be maladaptive coping strategies that principally serve to maintain the status quo, physiologically as well as psychologically. © 1992 Wiley-Liss, Inc.     

Validity for an Integrated Laboratory Analogue of Sexual Aggression and Bystander Intervention

This study sought to develop and validate an integrated laboratory paradigm of sexual aggression and bystander intervention. Participants were a diverse community sample (54% African American) of heterosexual males (N = 156) between 21 and 35 years of age who were recruited to complete the study with a male friend and an ostensibly single, heterosexual female who reported a strong dislike of sexual content in the media. Participants viewed a sexually explicit or nonsexually explicit film clip as part of contrived media rating task and made individual choices of which film clip to show the female confederate. Immediately thereafter, participants were required to reach consensus on a group decision of which film clip to show the female confederate. Subjecting a target to an unwanted experience with a sexual connotation was operationalized as selection of the sexually explicit video, whereas successful bystander intervention was operationalized as the event of one partner individually selecting the sexually explicit video but then selecting the nonsexually explicit video for the group choice. Results demonstrated that a 1‐year history of sexual aggression and endorsement of pertinent misogynistic attitudes significantly predicted selection of the sexually‐explicit video. In addition, bystander efficacy significantly predicted men's successful prevention of their male peer's intent to show the female confederate a sexually explicit video. Discussion focused on how these data inform future research and bystander intervention programming for sexual aggression. Aggr. Behav. 38:309–321, 2012. © 2012 Wiley Periodicals, Inc.     

Male alcohol‐related aggression as a function of type of drink

The present study tested the so‐called type‐of‐drink effect on aggression, that is, the idea that moderate acute alcohol intoxication elicits more aggression when the alcohol is drunk in the form of spirits than in the form of beer or wine. A computerized version of the Taylor “aggression machine” was used. Spirits‐drinking subjects drank 1.0 ml of 100% alcohol per kg body weight. To compensate for the lower alcohol concentration, beer‐ and wine‐drinking subjects drank 20% more. No significant differences were found between drinkers of different beverages in terms of blood alcohol levels. Results indicated that spirits elicited more direct physical aggression than either beer or wine. Three different possible explanations for this finding were discussed. Aggr. Behav. 25:401–408, 1999. © 1999 Wiley‐Liss, Inc.     

Comparison between BALB/cJ and BALB/cByJ mice in tests of social behavior and resident-intruder aggression

The behavior of male mice from two BALB strains, the BALB/cJ strain and the BALB/cByJ strain, was examined with a social behavior test and a resident-intruder paradigm. Prior to testing, the animals were isolated for 0, 2, 5, or 10 days. In the social behavior test the pairs of BALB/cJ mice spent more time in active social interaction than pairs of BALB/cByJ mice, although the latter strain showed more locomotor activity. BALB/cJ mice isolated for 5–10 days, when tested in a familiar environment were more aggressive than mice from the BALB/cByJ strain. In the resident-intruder paradigm, in which a resident BALB mouse was confronted with an intruder NIH Swiss mouse, the BALB/cByJ mice showed more social investigation in their home cage towards the intruders, but there were no significant differences between the two strains in the amounts of aggressive behavior exhibited. The results of these experiments suggest that there are some differences in the social behavior of the genetically related BALB/cJ and BALB/cByJ mice. However, the differences appear subtle and paradigm-specific.     

Construct validity of a competitive reaction-time aggression paradigm

This study tested the construct validity (convergent and discriminant) of a competitive reaction-time aggression paradigm. Seventy-nine males completed three trait aggression questionnaires and then competed on a reaction-time task whereby they received and delivered shocks to a fictitious opponent. Results demonstrated strong positive relationships between shock intensity administered and the trait measures of overt aggression but not with the measures unrelated to overt aggression. Results are discussed with regard to their contribution to the construct validity of the aggression paradigm used in this study. © 1995 Wiley-Liss, Inc.     

A Return Potential Measure of Setting Norms for Aggression

This study tested a classroom-level measure of norms based on J. Jackson's (1966) Return Potential Model. "Return potential" refers to the probability of approval of aggression in a given setting or group, and the return potential model allows quantification of different aspects of a setting's norms. Return potential measures were computed for unprovoked and provoked aggression. A pilot sample of 236 students in 11 classrooms and a main sample of 3,304 students in 158 classrooms completed this measure and a self-report measure of aggression. Results from hierarchical linear models showed that all measures of classroom return potential for aggression were significantly clustered by classrooms. Four return potential measures had main effects on aggression, and four measures showed variation in effects by grade or urban residence. Differences in clustering and effects by grade suggested age differences in the importance of different normative characteristics.     

Alcohol Reverses Religion's Prosocial Influence on Aggression

The relationship between religion and violence is controversial. Discrepant findings exist between survey studies and the limited number of experimental investigations of religiosity's influence on aggressive behavior. We have attempted to resolve this discrepancy by addressing previous limitations in the literature and assessing a heretofore‐untested moderator of religiosity and aggression: alcohol intoxication. This investigation included a community sample of 251 men and 269 women randomly assigned to either an acute alcohol intoxication condition or a placebo condition. Participants completed a series of questions drawn from standardized instruments of religiosity and spirituality prior to competing on an aggression laboratory paradigm in which electric shocks were received from, and administered to, a fictitious opponent under the guise of a competitive reaction‐time task. Hierarchical regression analyses revealed a significant beverage‐by‐religiosity interaction. Religiosity predicted lower levels of aggression for participants in the placebo group and higher levels of aggression for intoxicated participants. Results indicated that high religiosity coupled with alcohol intoxication may be a risk factor for aggression. This novel finding may help to clarify previous discrepancies in studies of religiosity and aggression.     

Influence of timing of post-weaning isolation on play fighting and serious aggression in the male golden hamster (Mesocricetus auratus)

Effects of timing of social isolation on play fighting and serious fighting were studied at different ages in male golden hamsters. Litters were isolated at 21, 35, and 65 days of age, and tested in a resident-intruder paradigm. Behaviors were compared within grous and with a fourth group of socially reared conspecifics. The earlier the pups were isolated, the more they engaged in play activities. Later, in adulthood, the aggression level of the same animals was retested using the same paradigm. The three isolated groups showed a high level of aggression, with significant differences among them. When compared with socially reared subjects, a reliable difference in the level of aggression was also found. These results support the view that early social experience is important, suggesting that isolation during early critical periods of socialization has a significant impact on play fighting, whereas short periods of isolation may be enough to trigger adult agonistic behavior. © 1994 Wiley-Liss, Inc.     

Retaliatory motivation enhances attributions of hostility when people process ambiguous social stimuli

We hypothesized that provocation and readiness to aggress (Retaliatory Motivation) would increase the tendency to construe the ambiguous actions of others as reflecting hostile intent. Male undergraduates were either verbally provoked or not provoked by a male experimenter and half were led to believe that they would be allowed to retaliate anonymously against the provoker in the form of a potentially damaging written evaluation. Participants then rated the hostility and aggressive intent of the characters in brief ambiguous scenarios of interpersonal conflict. According to prediction, men who were provoked and anticipated retaliation against their provoker rated the scenarios as containing hostility and aggression to a significantly greater extent than did non‐provoked or merely provoked participants. Results are discussed within a motivation‐based affective relevance model of perception. Aggr. Behav. 29:155–172, 2003. © 2003 Wiley‐Liss, Inc.