Alcohol and Aggression: Effects of Personal Threat on Human Aggression and Affective Arousal

Theorists have attempted to account for the relationship between alcohol intoxication and a wide range of aggressive behaviors by ascribing alcohol-related aggression to the disinhibiting effects of alcohol and to its disruptive effects on cognitive processes. Allocation of attention and situational threat have been thought to mediate alcohol-related aggression. In the present study, 72 male social drinkers received either alcohol, a placebo, or a nonalcoholic beverage and were exposed to either threatening or nonthreatening personal information. Measuring levels and duration of aggressive responses on a Taylor-Buss aggression machine, intoxicated subjects were found to be generally more aggressive under threatening than under nonthreatening information conditions. Intoxicated subjects also reported relatively large increases in anger, depression, and tension following the aggression task, which appeared to be affected by the type of information received. These findings concur with and refine previous models suggesting that alcohol focuses the drinker's attention to salient cues in threatening circumstances, thus increasing the likelihood of aggressive behavior.     

Alcohol-Related Aggression in Males and Females: Effects of Blood Alcohol Concentration, Subjective Intoxication, Personality, and Provocation

This study tested the combined predictive ability of blood alcohol concentration (BAC), subjective intoxication, and aggressive personality traits on physical aggression in males and females in Highland Low-provocation conditions. Sixty intoxicated White social drinkers (30 males and 30 females) competed against a fictitious opponent on a modified version of the Taylor aggression paradigm in which subjects both received and delivered electric shocks to their opponents in provoking and nonprovoking conditions. Provocation conditions (High and Low) were defined by the intensity of the shocks the subjects received. Aggression was operationalized as the intensity of the shocks selected by the subjects. Results indicated that, for males in the High-provocation condition, aggressive personality traits, subjective intoxication, and BAC were effective predictors of physical aggression. However, in the Low-provocation condition, only aggressive personality traits and BAC predicted aggression. None of the variables were effective predictors of aggression for intoxicated females.     

Male Physical Aggression as a Function of Alcohol Intoxication and Frustration: Experimental Results and Methodological Considerations

Forty-five undergraduate students were assigned to either an Alcohol, a Placebo, or a Control group. The alcohol dose was 0.80 g of 100% alcohol/kg body weight. Subjects were informed that they could win a sum of money depending on the performance of a partner. They then supervised the partner over a series of trials on a visual scan test and could influence the partner by either giving an uncomfortable electric shock (aggressive alternative) or a comfortable vibration (nonaggressive alternative) at each incorrect response from the partner. Both alternatives were said to be equally instrumental in reaching the goal of winning the money and both could be varied in intensity on a 10-point scale and without limits in terms of duration. Aggression was measured as number of aggressive responses chosen, and in terms of intensity and duration. Nonaggression was measured in terms of intensity and duration. Intoxicated subjects did not increase their aggression but all groups chose significantly more nonaggressive responses and did so with higher intensity and duration. Frustration did not significantly affect these types of responding. Results are discussed in terms of methodological considerations and the importance of using realistic experimental paradigms is stressed. Also, theoretical implications are discussed.     

Alcohol and Heightened Aggression in Individual Mice

The objective of the current research was to study the large individual differences in alcohol effects on aggressive behavior under systematically varied conditions in experimental protocols with mice. Three experiments were conducted with outbred Swiss-Webster derived mice that identified those individuals whose aggressive behavior was reliably heightened by low acute alcohol doses. In all experimental protocols, low alcohol doses were orally administered to a “resident” male mouse that subsequently confronted an “intruder” opponent for 5 min while all salient elements of aggressive behavior and motor activities were quantified. In all three experiments, alcohol (1.0 g/kg) heightened aggressive behavior by at least two standard deviations of the individual's water vehicle control mean in 27% of the mice. In 64% of mice, no reliable change in aggressive behavior was detected after the identical alcohol treatment, and in 9% of the mice alcohol decreased aggressive behavior. Experiments differed in protocol indicating that these aggression-heightening effects were evident in resident mice that were either maintained at restricted or unlimited amounts of food, housed singly or in breeding pairs with a female partner, and conditioned to perform daily a food-reinforced task or remained undisturbed. The first experiment found the aggression-heightening effects to persist during weekly challenges for at least 2 months (n= 8 of 30). The second experiment showed these effects at intervals from 5 to 60 min after alcohol administration. Blood alcohol concentrations reached peak level within 5 to 10 min after oral administration in mice that had confronted an intruder. Those mice in whom alcohol heightened aggressive behavior (n= 21) did not differ from those that showed suppressed levels (n= 9) in terms of blood alcohol concentrations (79.6 vs. 82.4 mg%), suggesting that the intensity and frequency of aggressive behavior after alcohol were not directly dependent on the amount of alcohol in the circulation. The third experiment revealed that alcohol's (0.1 to 5.6 g/kg) effects on heightened aggressive behavior (n= 11) are dissociated from those on concurrently measured high- or low-rate operant performance as engendered by a multiple FR 30-FI 600 sec schedule of reinforcement. Current results indicate that this alcohol effect is relatively specific to aggressive behavior in individual animals, offering the opportunity for neuropharmacological and molecular characterization.     

Aggressive and Nonaggressive Behavior as a Function of Alcohol Intoxication and Frustration in Women

An experiment tested whether alcohol increases aggression in women in a situation in which both an aggressive and a nonaggressive response alternative of equal instrumentality and of equal variability are available. Subjects were assigned to one of three groups, namely, an alcohol, a placebo, or a control group. The alcohol dose was 1.0 ml of pure alcohol/kg body weight. After drinking their respective drink, subjects were instructed to supervise a bogus partner on a visual scan test over a series of trials. Each time this partner made a mistake, subjects could either give an uncomfortable electric shock (scale 1 to 10) or a comfortable vibration (scale 1 to 10) to the partner. Aggressive and nonaggressive behavior was measured as numbers, intensities, and durations of shocks or vibrations, respectively. Neither alcohol nor frustration differentiated the groups on aggressive or nonaggressive behavior. All groups were significantly more inclined to use the nonaggressive alternative irrespective of alcohol dose and level of frustration. In conclusion it was stated that women do not increase their aggression as a function of alcohol in a situation with more than one response alternative available. The need to incorporate gender differences as to aggressive effects of alcohol was stressed.     

Smoking and Intoxication after Alcohol Challenge in Women and Men: Genetic Influences

In an earlier analysis, men and women who were current or former smokers were found to report feeling less intoxicated on average than nonsmokers after ingestion of a challenge dose of alcohol. Here, we examine whether differences in subjective response to alcohol and a tendency to smoke cigarettes are transmitted together in families; and, if so, whether this association might be entirely explained by the same heritable factors that influence alcohol intake (as we might expect if both smoking and subjective intoxication are influenced by some general susceptibility for substance use). Alcohol challenge data on 388 Australian male and female twins (194 complete pairs) were reanalyzed using multivariate genetic analysis to evaluate the association between cigarette smoking and self-report intoxication after a standard dose of alcohol. In women, we could not reject the hypothesis of complete genetic overlap between effects on intoxication rating and history of smoking, and a significant residual genetic correlation between smoking and postalcohol intoxication persisted even when genetic influences on alcohol consumption were controlled for. In men, the familial association seemed to be largely environmentally mediated and associated with differences in drinking history. These findings prompt the question of whether, in some individuals, cigarette smoking may contribute to the development of tolerance to the effects of alcohol.     

Interactive Effects of Cumulative Stress and Impulsivity on Alcohol Consumption

Background: Alcohol addiction may reflect adaptations to stress, reward, and regulatory brain systems. While extensive research has identified both stress and impulsivity as independent risk factors for drinking, few studies have assessed the interactive relationship between stress and impulsivity in terms of hazardous drinking within a community sample of regular drinkers. Methods: One hundred and thirty regular drinkers (56M/74F) from the local community were assessed for hazardous and harmful patterns of alcohol consumption using the Alcohol Use Disorders Identification Test (AUDIT). All participants were also administered the Barratt Impulsiveness Scale (BIS‐11) as a measure of trait impulsivity and the Cumulative Stress/Adversity Checklist (CSC) as a comprehensive measure of cumulative adverse life events. Standard multiple regression models were used to ascertain the independent and interactive nature of both overall stress and impulsivity as well as specific types of stress and impulsivity on hazardous and harmful drinking. Results: Recent life stress, cumulative traumatic stress, overall impulsivity, and nonplanning‐related impulsivity as well as cognitive and motor‐related impulsivity were all independently predictive of AUDIT scores. However, the interaction between cumulative stress and total impulsivity scores accounted for a significant amount of the variance, indicating that a high to moderate number of adverse events and a high trait impulsivity rating interacted to affect greater AUDIT scores. The subscale of cumulative life trauma accounted for the most variance in AUDIT scores among the stress and impulsivity subscales. Conclusions: Findings highlight the interactive relationship between stress and impulsivity with regard to hazardous drinking. The specific importance of cumulative traumatic stress as a marker for problem drinking is also discussed.     

Fetal Alcohol Effects: Mechanisms and Treatment

This article represents the proceedings of a symposium at the 2000 ISBRA Meeting in Yokohama, Japan. The chair was Edward P. Riley. The presentations were (1) Does alcohol withdrawal contribute to fetal alcohol effects? by Jennifer D. Thomas and Edward P. Riley; (2) Brain damage and neuroplasticity in an animal model of binge alcohol exposure during the third trimester equivalent, by Charles R. Goodlett, Anna Y. Klintsova, and William T. Greenough; (3) Ganglioside GM1 reduces fetal alcohol effects, by Basalingappa L. Hungund; and (4) Fetal alcohol exposure alters the wiring of serotonin system at mid-gestation, by F. Zhou, Y. Sari, Charles Goodlett, T. Powrozek, and Ting-Kai Li.     

Effects of Assessment Frequency on Subjective Intoxication Ratings After Alcohol Consumption

BACKGROUND: It is common for subjective intoxication measures to be administered frequently throughout an experimental session. It is unclear, however, whether repeated assessments affect the experience of intoxication. This study examined the effect of assessing subjective intoxication levels during alcohol consumption on subsequent perceptions of intoxication after drinking. METHODS: Forty-two participants consumed a moderate dose of alcohol (men, 82 g/kg; women, 0.74 g/kg) during a 30-min period. Participants either reported or did not report subjective intoxication levels at 10-min intervals during the drinking period. After the drink, all participants rated their level of subjective intoxication on several occasions. RESULTS: Individuals who reported their intoxication during the drinking period reported higher levels after consumption than did those who did not rate their intoxication during drinking. CONCLUSIONS: These data suggest the potential for reactivity effects when conducting repeated assessments of perceived subjective intoxication.     

Functional Imaging of Cognitive Control During Acute Alcohol Intoxication

Background: The anterior cingulate and several other prefrontal and parietal brain regions are implicated in error processing and cognitive control. The effects of different doses of alcohol on activity within these brain regions during a functional magnetic resonance imaging (fMRI) task where errors are frequently committed have not been fully explored. Methods: This study examined the impact of a placebo [breath alcohol concentration (BrAC) = 0.00%], moderate (BrAC = 0.05%), and high (BrAC = 0.10%) doses of alcohol on brain hemodynamic activity during a functional MRI (fMRI) Go/No‐Go task in 38 healthy volunteers. Results: Alcohol increased reaction time and false alarm errors in a dose‐dependent manner. fMRI analyses showed alcohol decreased activity in anterior cingulate, lateral prefrontal cortex, insula, and parietal lobe regions during false alarm responses to No‐Go stimuli. Conclusions: These findings indicate that brain regions implicated in error processing are affected by alcohol and might provide a neural basis for alcohol’s effects on behavioral performance.     

Antisocial Personality Disorder and Alcohol-Induced Aggression

This study compared the effects of alcohol on aggressive responding between subjects with antisocial personality disorder (ASPD) and subjects without ASPD. Eighteen alcohol drinking subjects (10 subjects without ASPD and 8 subjects with ASPD) underwent testing on a laboratory measure of aggression, the Point Subtraction Aggression Paradigm, after consumption of placebo and three doses of alcohol (0.25 g/kg, 0.5 g/kg, and 1.0 g/kg). There was a significant difference in the effect of alcohol on aggressive responding on the Point Subtraction Aggression Paradigm between subjects with ASPD and subjects without ASPD. Subjects with ASPD had a greater increase in aggressive responding after alcohol, compared with non-ASPD subjects. There was no difference between the two groups in the effect of alcohol on monetary-reinforced responding.     

Intoxication after an Acute Dose of Alcohol: An Assessment of Its Association with Alcohol Consumption Patterns By using Twin Data

We examined the hypothesis that genetically determined differences in sensitivity to alcohol explain some of the genetic variation in alcohol consumption pattern. Self-report data on average weekly alcohol consumption and self-ratings of intoxication after a standard dose of ethanol (0.75 g/kg body weight), used as an index of sensitivity, were obtained on 206 Australian twin pairs. Significant genetic covariance between weekly consumption and level of intoxication after alcohol intake was found in males, lower ratings of intoxication being associated with increased consumption. However, when direction of causation models were fitted to the male twin data, the hypothesis that decreased sensitivity was a cause of increased consumption was rejected. The major causal effect was that of weekly consumption on level of sensitivity. A similar, although nonsignificant, trend was observed in females. The strength of the association between self-report of average weekly consumption and level of intoxication after a standard dose of alcohol supports the validity of the former measure.