Further experiments on the social interactions of domestic “Norway” rats

Domestic rats, Rattus norvegicus, aged nearly one year, were studied in artificial colonies in large cages with attached nest boxes. As in previous experiments on younger domestic rats, but not those on wild rats, the colonies were peaceful. Questions concerning the “aggressive” or “agonistic” behavior of domestic rats are further discussed.     

Social dominance and individual aggressiveness

Male rats exhibiting high, moderate, or low levels of offensive aggressive behavior in interactions with intruders in their home cage were grouped in mixed-sex colonies with 1 male of each aggression-level group in each colony. Agonistic interactions measured 1, 2, 3, 7, 14, 21, and 22 days after colony formation indicated that highly aggressive males on pretests continued to be more aggressive, becoming the dominant colony male in five of seven colonies and attacking intruders more often than less aggressive males. In the two remaining colonies the moderately aggressive male became dominant. This relationship, which was consistent over a number of indices, including offensive and defensive behaviors, and wound counts and wound sites, was seen even when a substantial weight differential favored the less aggressive animal. Dominance relationships were rapidly established and within-group fighting declined significantly over the 21-day test period. Pretest offensive levels also influenced the behavior of subordinates, with high or moderately aggressive subordinates showing more defense in interactions with dominants and receiving more wounds than did low-aggression subordinates. Dominant males also showed more defense in interacting with those subordinates which had been more aggressive during pretests. This pattern of results suggests that aggression level of the subordinate as well as the dominant may be an important factor determining the intensity of agonistic interactions in male rats.     

Individual differences in interspecific aggressiveness: Mouse-killing in rats after isolation

Measures of extraversion and neuroticism in rats are related to aggressive behaviour in two strains of rats. Isolated rats and rats reared together, of the Sprague-Dawley and Wistar strains, were submitted to an aggressiveness test. The results show that isolation generates and/or increases mouse-killing behaviour only in Wistar rats which are more emotional (neurotic) than Sprague-Dawley rats. The two strains do not differ significantly in their open-field ambulation (extraversion), although Wistar rats tend to be less ambulatory. Within the Wistar strain, the results showed the same trend, that is, the more emotional and less ambulatory rats (dysthymics) are the ones who became killers after isolation. The Sprague-Dawley strain does not show any significant aggressive behaviour after isolation.     

Physical activity participation and physical aggression in children and adolescents: A systematic review and meta-analysis

BackgroundAggressive behaviour is a substantial behavioural problem in children and adolescents. This review systematically summarises the current evidence on the relationship between physical activity participation and aggressive behaviour and quantifies the effects of physical activity interventions on aggression in children and adolescents.MethodsStudies were identified through a search of five electronic databases (PsycINFO, SPORTDiscus, MEDLINE, CINAHL and Web of Science) with combinations of three groups of keywords. Two independent reviewers screened and extracted data from the individual studies. The reporting quality and publication bias were assessed. The relationship between physical activity participation and aggressive behaviour was systematically summarized. Data (effect sizes) were pooled to investigate the effects of physical activity interventions on aggressive behaviour. A moderator meta-analysis was performed to identify potential moderators of the effects of physical activity interventions on aggressive behaviour.ResultsNineteen studies met the inclusion criteria. The relationship between physical activity participation and aggressive behaviour was mixed. A significant reduction in aggressive behaviour was observed after physical activity interventions (k = 8, SMD = −0.53, 95% CI [−0.27, −0.79], p < 0.001). The moderator meta-analysis showed that physical activity interventions involving team-based physical activity had greater effects than those involving individual-based physical activity (β = 0.42, SE = 0.18, p = 0.02). In addition, interventions involving physical activity alone were more effective in reducing aggressive behaviour than those that combined physical activity with other activities such as a philosophy course (β = −0.63, SE = 0.11, p < 0.001).ConclusionThe current meta-analysis presents evidence for the effect of physical activity interventions on aggressive behaviour in children and adolescents. Physical activity–only interventions involving team-based physical activity might be used for preventing or reducing aggressive behaviour in children and adolescents. Possible mechanisms, methodological strengths and weaknesses, implications, and suggestions for future studies were discussed.     

Who took the "x" out of expectancy-value theory? A psychological mystery, a substantive-methodological synergy, and a cross-national generalization

Expectancy-value theory (EVT) is a dominant theory of human motivation. Historically, the Expectancy × Value interaction, in which motivation is high only if both expectancy and value are high, was central to EVT. However, the Expectancy × Value interaction mysteriously disappeared from published research more than 25 years ago. Using large representative samples of 15-year-olds (N = 398,750) from 57 diverse countries, we attempted to solve this mystery by testing Expectancy × Value interactions using latent-variable models with interactions. Expectancy (science self-concept), value (enjoyment of science), and the Expectancy × Value interaction all had statistically significant positive effects on both engagement in science activities and intentions of pursuing scientific careers; these results were similar for the total sample and for nearly all of the 57 countries considered separately. This study, apparently the strongest cross-national test of EVT ever undertaken, supports the generalizability of EVT predictions--including the "lost" Expectancy × Value interaction.     

Septal lesions and biting attacks in rats bidirectionally selected for emotionality

Twenty-nine colonies composed of one female and two male rats of high or low emotional strain were established. A dominant male of each colony was identified based on its attacks on an intruder rat. It was found that dominant males of the low emotional strain colonies were significantly more aggressive than those of the high emotional strain. Septal lesions or sham operations were given to dominant males of both strain colonies. Intruder tests were followed and several aggressive behaviors were measured by VTR observation. Biting attacks of the high emotional strain decreased for 10 days after septal latencies were shortened by septal lesions. Lesions X Strain interaction was significant. These results suggest that septal lesion effects on biting attacks are influenced by artificial genetic operations.     

A beverage-specific measure of expectancies for malt liquor: development and initial testing

Malt liquor (ML) is a unique, high alcohol content beverage marketed to encourage heavy drinking. We developed the Malt Liquor Expectancy Questionnaire (MLEQ), a beverage-specific measure of alcohol expectancies, and examined its association with typical weekly ML use, typical weekly alcohol use, and alcohol problems. Forty positive and 40 negative expectancy items were administered to a sample of 639 young adults who regularly consumed ML. Exploratory and confirmatory factor analyses led to the development of the 30-item MLEQ. The MLEQ consists of two positive (i.e., Social Facilitation and Enjoyment, Enhanced Sexuality) and two negative factors (i.e., Aggression and Negative Consequences; Impairment and Physical Symptoms) that possess good internal consistency, test-retest reliability, and convergent validity. The psychometrically sound MLEQ contributes to the limited research on beverage-specific expectancies and heavy drinking.     

Impact of background characteristics and gender–role attitudes on Chinese perceptions of selection criteria in employment

A random sample of 699 (327 men and 372 women) currently employed Chinese subjects participated in a study that examined their perceptions of common selection criteria in employment. Results of factor analysis showed that various selection criteria could be grouped under four underlying factors. In general, participants rated the Psychological Attribute factor as the most important criterion, followed closely by the Experience and Skill factor, and viewed the Physical Attribute and Demographic factors as the least important. Results of hierarchical regression analyses showed that participants'gender–role attitudes, especially those towards men's and women's roles in education, marriage and social interactions, were the most salient predictors of their perceptions towards the selection criteria. This remained true even after controlling for participants' background characteristics. Participants' gender, age and educational attainment were also predictive of their appraisal of various selection criteria in employment.     

The development of social information processing and aggressive behaviour: Current issues

The social information processing (SIP) model is an important element in theoretical accounts of the development of aggressive behaviour. Aggressive behaviour is associated with and predicted by specific social information-processing patterns and interventions targeting these patterns are relatively effective. The present article discusses three directions in which further progress can be made. First, the SIP model may be improved to take better account of emotional processes. Second, issues concerning the validity of SIP assessment need to be resolved. Third, differential development of SIP needs to be studied and to be related to development of specific aggressive behaviour patterns. Recent findings concerning these three issues are reviewed and directions for research are discussed.     

A Guide to the Literature on Aggressive Behavior

The Guide to the Literature on Aggressive Behavior is based on Source Publications provided by ASCA (Automatic Subject Citation Alert) from the ISI (Institute for Scientific Information), 3501 Market Street, Philadelphia, PA 19104, U.S.A. Telephone (215) 386–0100. The following key words are used in weekly computer searches of nearly 5,800 science, technical, and social science journals from around the world: Attack, Fight, Dominant, Aggression, Violence, Agonistic, Hostility, Anger Articles are drawn from ISI Science Citation Index, Social Sciences Citation Index, and Current Contents. Journals surveyed include the following general areas: Agricultural, Biological, and Environmental Science Engineering, Technology and Applied Sciences Medical and Life Sciences Physical and Chemical Sciences Social and Behavioral Sciences Full texts of articles may be obtained from ISI's Genuine Article, which supplies tear sheets or photocopies.     

A Guide to the Literature on Aggressive Behavior

The Guide to the Literature on Aggressive Behavior is based on Source Publications provided by ASCA (Automatic Subject Citation Alert) from the ISI (Institute for Scientific Information∥, 3501 Market Street, Philadelphia, PA 19104, U.S.A. Telephone (215) 386–0100. The following key words are used in weekly computer searches of nearly 5,800 science, technical, and social science journals from around the world: Attack, Fight, Dominant, Aggression, Violence, Agonistic, Hostility, Anger Articles are drawn from ISI Science Citation Index, Social Sciences Citation Index, and Current Contents. Journals surveyed include the following general areas: Agricultural, Biological, and Environmental Science Engineering, Technology and Applied Sciences Medical and Life Sciences Physical and Chemical Sciences Social and Behavioral Sciences Full texts of articles may be obtained from ISI's Genuine Article, which supplies tear sheets or photocopies.     

A Guide to the Literature on Aggressive Behavior

The Guide to the Literature on Aggressive Behavior is based on Source Publications provided by ASCA (Automatic Subject Citation Alert) from the ISI (Institute for Scientific Information∥, 3501 Market Street, Philadelphia, PA 19104, U.S.A. Telephone (215) 386–0100. The following key words are used in weekly computer searches of nearly 5,800 science, technical, and social science journals from around the world: Attack, Fight, Dominant, Aggression, Violence, Agonistic, Hostility, Anger Articles are drawn from ISI Science Citation Index, Social Sciences Citation Index, and Current Contents. Journals surveyed include the following general areas: Agricultural, Biological, and Environmental Science Engineering, Technology and Applied Sciences Medical and Life Sciences Physical and Chemical Sciences Social and Behavioral Sciences Full texts of articles may be obtained from ISI's Genuine Article, which supplies tear sheets or photocopies.     

A guide to the literature on aggressive behavior

The Guide to the Literature on Aggressive Behavior is based on Source Publications provided by ASCA (Automatic Subject Citation Alert) from the ISI (Institute for Scientific Information), 3501 Market Street, Philadelphia, PA 19104, U.S.A. Telephone (215) 386–0100. The following key words are used in weekly computer searches of nearly 5,800 science, technical, and social science journals from around the world: Attack, Fight, Dominant, Aggression, Violence, Agonistic, Hostility, Anger Articles are drawn from ISI Science Citation Index, Social Sciences Citation Index, and Current Contents. Journals surveyed include the following general areas: Agricultural, Biological, and Environmental Science Engineering, Technology and Applied Sciences Medical and Life Sciences Physical and Chemical Sciences Social and Behavioral Sciences Full texts of articles may be obtained from ISI's Genuine Article, which supplies tear sheets or photocopies.     

A Guide to the Literature on Aggressive Behavior

The Guide to the Literature on Aggressive Behavior is based on Source Publications provided by ASCA (Automatic Subject Citation Alert) from the ISI (Institute for Scientific Information), 3501 Market Street, Philadelphia, PA 19104, U.S.A. Telephone (215) 386–0100. The following key words are used in weekly computer searches of nearly 5,800 science, technical, and social science journals from around the world: Attack, Fight, Dominant, Aggression, Violence, Agonistic, Hostility, Anger Articles are drawn from ISI Science Citation Index, Social Sciences Citation Index, and Current Contents. Journals surveyed include the following general areas: Agricultural, Biological, and Environmental Science Engineering, Technology and Applied Sciences Medical and Life Sciences Physical and Chemical Sciences Social and Behavioral Sciences Full texts of articles may be obtained from ISI's Genuine Article, which supplies tear sheets or photocopies.     

The judgement of behaviour as aggressive and sanctionable

The influence of the factors norm deviation, intent, and injury, on the judgement of a critical act as aggressive and sanctionable was tested using a 2 × 2 × 2 factorial design. Scenarios depicting aggressive interactions represented the experimental conditions. 859 school children rated these scenarios on bipolar rating scales. The results show that norm deviation, intent, and injury, are important criteria for the interpretation of aggressive behaviour. Judging an action as sanctionable proved to be more sensitive for the variation of factors than the interpretation of behaviour as aggressive. In addition, an analysis of how the scenarios representing the experimental conditions were subjectively interpreted by the subjects was carried out. This showed that all combinations of the three definition criteria are psychologically meaningful. However, preferences were observed for specific interpretation patterns.     

A Guide to the Literature on Aggressive Behavior

The Guide to the Literature on Aggressive Behavior is based on Source Publications provided by ASCA (Automatic Subject Citation Alert) from the ISI (Institute for Scientific Information∥, 3501 Market Street, Philadelphia, PA 19104, U.S.A. Telephone (215) 386–0100. The following key words are used in weekly computer searches of nearly 5,800 science, technical, and social science journals from around the world: Attack, Fight, Dominant, Aggression, Violence, Agonistic, Hostility, Anger Articles are drawn from ISI Science Citation Index, Social Sciences Citation Index, and Current Contents. Journals surveyed include the following general areas: Agricultural, Biological, and Environmental Science Engineering, Technology and Applied Sciences Medical and Life Sciences Physical and Chemical Sciences Social and Behavioral Sciences Full texts of articles may be obtained from ISI's Genuine Article, which supplies tear sheets or photocopies.     

A Guide to the Literature on Aggressive Behavior

The Guide to the Literature on Aggressive Behavior is based on Source Publications provided by ASCA (Automatic Subject Citation Alert) from the ISI (Institute for Scientific Information), 3501 Market Street, Philadelphia, PA 19104, U.S.A. Telephone (215) 386–0100. The following key words are used in weekly computer searches of nearly 5,800 science, technical, and social science journals from around the world: Attack, Fight, Dominant, Aggression, Violence, Agonistic, Hostility, Anger Articles are drawn from ISI Science Citation Index, Social Sciences Citation Index, and Current Contents. Journals surveyed include the following general areas: Agricultural, Biological, and Environmental Science Engineering, Technology and Applied Sciences Medical and Life Sciences Physical and Chemical Sciences Social and Behavioral Sciences Full texts of articles may be obtained from ISI's Genuine Article, which supplies tear sheets or photocopies.     

A Guide to the Literature on Aggressive Behavior

The Guide to the Literature on Aggressive Behavior is based on Source Publications provided by ASCA (Automatic Subject Citation Alert) from the ISI (Institute for Scientific Information∥, 3501 Market Street, Philadelphia, PA 19104, U.S.A. Telephone (215) 386–0100. The following key words are used in weekly computer searches of nearly 5,800 science, technical, and social science journals from around the world: Attack, Fight, Dominant, Aggression, Violence, Agonistic, Hostility, Anger Articles are drawn from ISI Science Citation Index, Social Sciences Citation Index, and Current Contents. Journals surveyed include the following general areas: Agricultural, Biological, and Environmental Science Engineering, Technology and Applied Sciences Medical and Life Sciences Physical and Chemical Sciences Social and Behavioral Sciences Full texts of articles may be obtained from ISI's Genuine Article, which supplies tear sheets or photocopies.     

A Guide to the Literature on Aggressive Behavior

The Guide to the Literature on Aggressive Behavior is based on Source Publications provided by ASCA (Automatic Subject Citation Alert) from the ISI (Institute for Scientific Information∥, 3501 Market Street, Philadelphia, PA 19104, U.S.A. Telephone (215) 386–0100. The following key words are used in weekly computer searches of nearly 5,800 science, technical, and social science journals from around the world: Attack, Fight, Dominant, Aggression, Violence, Agonistic, Hostility, Anger Articles are drawn from ISI Science Citation Index, Social Sciences Citation Index, and Current Contents. Journals surveyed include the following general areas: Agricultural, Biological, and Environmental Science Engineering, Technology and Applied Sciences Medical and Life Sciences Physical and Chemical Sciences Social and Behavioral Sciences Full texts of articles may be obtained from ISI's Genuine Article, which supplies tear sheets or photocopies.     

Symptom patterns in late luteal-phase dysphoric disorder

The symptom patterns of 180 women with prospectively confirmed late luteal-phase dysphoric disorder (LLPDD) were examined using a careful application of factor and cluster analytic techniques. Factor analysis of premenstrual change scores on 33 common premenstrual syndrome symptoms yielded four orthogonal factors that were consistent across two sets of menstrual cycle data. These were a negative affect dimension with concomitant behavioral changes, physical symptoms, agitation, and positive arousal. Cluster analysis of factor scores grouped patients into one of five symptom patterns, the most common of which is a general distress cluster, characterized by symptoms across all dimensions. The LLPDD symptom groups identified are remarkably consistent with those of earlier studies using both normative and clinic samples, and consideration of symptom pattern differences in future research may greatly increase our understanding of this disorder.