Dominance-subordinance in cohabiting pairs of adult rats: Effects on Aggressive behavior

Following an initial intruder aggression test, 10 pairs of adult male rats matched on aggressiveness were formed. The first 20 min of paired cohabitation were used to determine dominance and subordinance between pau members. Residents judged to be dominant from this observation session gained significantly more weight during cohabitation and exhibited significantly more aggression on the second aggression test than their subordinate counterparts. Significant correlations among various measures of aggression were found, but open field performance did not correlate, with the measures of aggression nor did changes in open field scores reflect changes in aggression.     

The role of hyperdipsia in aggression following septal lesions in rats

Lesions of the septum in animal subjects are known to produce an increase in aggressiveness and an increase in water intake. A series of experiments was carried out to examine the possibility that aggression was secondary to hyperdipsia. When rats with septal lesions were restricted to preoperative levels of water intake, aggression scores declined significantly. When animals without lesions were preloaded, with either water or saline, aggression increased. Neither decreased shock threshold nor increased cell hydration provided a full explanation for the results. It is suggested that the aversive nature of the stomach turgescence caused by increased water intake may be an additional mediating factor in septal aggression.     

Test-dependent expression of behavioral syndromes: A study of aggressiveness,activity, and stress of chub

Aggressiveness has been one of the behavioral traits most examined with various standard testing methods. We used two distinct methods (the mirror and the real opponent tests) to evaluate individual aggression and relate it to the activity and individual stress of chub (Squalius cephalus L.). Three hypotheses were formulated and tested: (a) there is a significant positive relationship between the aggressiveness of individuals measured with the mirror and the real opponent tests, indicating their convergent validity; (b) the irregularities in response to the aggressiveness and activity tests lead to the context-specific expression of the behavioral syndromes; and (c) there is a significant positive relationship between the stress induced in individuals by both tests of aggressiveness, demonstrating individually consistent stress-coping strategies. The first and the second hypothesis were confirmed, while the third hypothesis was rejected. Our results suggest that particular tests of aggressiveness could act as a situation with high strength, leaving little variation between individual responses. Thus, we propose that for the proper interpretation of various studies using different tests to study identical behavioral traits, it is important to consider the convergent validity of not only the tested behavioral traits but also the individual stress responses. The chub also showed stress relieve through aggressiveness, suggesting the species as a prospective animal model to the study interaction between the stress and the aggressiveness. A detailed aggression ethogram of chub was provided to facilitate the use of this specie in future studies.     

Effects of alcohol and frustration on experimental graffiti

This study aimed to examine effects between alcohol and frustration in regard to graffiti. Forty-two subjects, 21 men and 21 women were randomly assigned in equal numbers to each of the three experimental groups, namely a Control group, an Alcohol group, and an Alcohol+Frustration group (alcohol dose: 1 ml 100% alcohol/kg body weight). For the purposes of this experiment, a test (AET) was constructed that provided scores of "scrawling-graffiti" (i.e., the amount of scrawling on pictures), "destruction", "aggression", and "sexuality". An elaboration test and a test measuring the "dispositional optimism" were also applied. The primary results indicated that (a) the Alcohol+Frustration group scored significantly higher on scrawling-graffiti compared to the Control group, (b) female subjects performed graffiti-scrawling to a greater extent than male subjects in all three groups, (c) women scored significantly higher on elaboration as compared to men. These results were interpreted as supporting the hypothesis that alcohol intake by itself is unlikely to induce destructive behavior unless accompanied by a "provocative" factor (e.g. frustration) that precipitates the putative expressions of aggressiveness.     

The Scope of Client Aggression Toward Social Workers in Israel

The phenomenon of client violence toward social workers has been documented in various parts of the world. The goal of this study is to describe the phenomenon and explore the relationship pattern between contextual variables and clients’ aggression. The study encompassed a sample of 645 workers in 34 municipal social service agencies. Of the entire sample, 80% reported being exposed to some form of aggression at least once over the last 3 months. The findings highlight 2 broad axes related to client aggressiveness: frequency and level of aggression. With respect to frequency, we can discern a continuum running from common types of aggressive behaviors to rare ones. The other axis focuses on the level of aggressiveness used, from minor types of client aggression, such as verbal assaults and threats, increasing to more severe ones, such as property damage, and, finally, to physical injury. The routineness of aggression in the work environment lends it the appearance of being normal, and functioning in such an environment desensitizes social workers to clients’ aggressiveness. Also examined and discussed are organizational and personal factors that contribute to the aggressive behavior of clients, including seniority, gender, workload, inadequate service conditions, and coworkers’ aggressive behavior.     

Predictors of women's aggressive driving behavior

Predictors of women's aggressive driving behavior were explored in a study involving 256 female motorists. Sex role orientation, dispositional aggressiveness, age, and annual mileage were measured as independent variables, and aggressive driving behavior was included as the dependent variable. Stepwise hierarchical regression analysis showed that age was negatively related to driving aggression, whereas annual mileage had a positive relationship with driving aggression. Dispositional aggressiveness was a significant predictor of driving aggression. Of the two components of sex role orientation, only femininity was associated with driving aggression, with higher femininity scores predicting lower aggressive driving scores. Masculinity failed to predict aggressive driving, as did the interaction of masculinity and femininity. In combination, the predictors explained 29% of the variance in women's aggressive driving. The results are discussed with respect to the role of dispositional variables as predictors of driving aggression in women. Aggress. Behav. 00:1–10, 2005. © 2005 Wiley‐Liss, Inc.     

The victim's reaction to an attack as a function of his perception of the attacker following a verbal insult

This study investigated the role of perception in the victim's behaviour following a verbal attack. It was expected that the victim's counterattack and evaluation of attacker would be influenced by: (a) the victim's level of aggressiveness; (b) the attacker's perceived level of aggressiveness; (c) the attacker's status (prestige in the classroom); and (d) retaliation threat for counterattack. High and low aggressive subjects (victim's) were randomly assigned to one of four conditions differing in the attacker's attributed level of aggression and status. Half of the subjects in each condition received a retaliation threat treatment. The victims were interacting with an assumed partner (attacker) in a guessing game during which they were insulted. After each insult the victim could counterattack by withholding a monetary reward from the attacker. At the end, the victim rated his attacker on aggressiveness, potency and social desirability. The results indicated that there were significant main effects of the victims level of aggressiveness, the attacker's status and retaliation threat. There was also a significant interaction between victim's and attacker's aggressiveness, for the two dependent variables. In addition, victim's behaviour was influenced by the interaction between attacker's status and his aggressiveness.     

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.     

Concurrent and predictive validity of self-reported aggressiveness

The subjects (60 boys) were drawn from the sample of a longitudinal study of social development and represented extremely aggressive, anxious, constructive, and submissive behaviour at the age of 8. They were presented with three question series concerning (1) their responses to aggressive attacks; (2) reactions in frustration situations presented in short stories; and (3) their aggressive initiatives. In each series the type of aggressive behaviour, attacker, victim, and other situational factors were systematically varied. In series 2 the type of response, open-ended or forced-choice, was also varied. The results showed that the most valid way of studying boys' self-observations on their aggressive behaviour was to ask if they attack somebody without a specific reason (series 3). This correlated with contemporaneous overt aggression at the age of 8 and predicted aggressiveness and various characteristics of antisocial aggressive development at the ages of 14 and 19. Self-observations on one's physical aggression were more valid for ratings of overt aggressiveness than on verbal aggression. The open-ended or forced-choice type of response did not affect the validity of aggressive responses. Of the categories of nonaggression, ‘conciliatory responses’ had the highest concurrent and predictive validity for constructiveness and other indicators of strong self-control.     

GENETIC AND SOCIAL CAUSES OF AGGRESSIVE BEHAVIOUR IN MICE

L agerspetz , K irsti . Genetic and social causes of aggressive behaviour in mice. Scand. J. Psychol ., 1961, 2 , 167—-173.—Significant differences in the aggressiveness of mice selected for aggressiveness and non-aggressiveness have been found to occur in the 2nd and 3rd generation of selective breeding. In S _a, motor activity scores were significantly higher in mice of the aggressive than of the non-aggressive strain. Defecation and ambulation scores obtained both in a standardized open-field test and in connection with the aggression measurements showed that the S₃ descendants of the aggressive mice were emotionally less reactive than the members of the 3rd non-aggressive generation. Defeats tend to decrease, victories to increase the level of aggressiveness in mice, but the aggression scores tend to return to the original level after the termination of the experiments.     

A new approach to explain aggression

Two separate experiments are reported. They show the methodological difficulties and subsequent conceptual complications in Berkowitz's modified frustration-aggression theory and Zillman's theory of aggression. There was a marginally significant difference in the verbal measure of aggression favouring subjects aroused by frustration over subjects aroused by exercise, but not on the behavioral measure of aggression. Exp. II was conducted to test an alternative hypothesis, deduced from Fraisse's theory of emotion, which states that subjects respond more aggressively when confronted with unexpected than with expected annoyance. All six measures of aggression confirmed the hypothesis. The results of these two experiments indicate conceptual and methodological difficulties inherent in Berkowitz's modified frustration-aggression theory and Zillman's theory of aggression; they also suggest that Fraisse's theory of emotion presents a better model of aggression.     

Effects of early exposure to intermale aggression on the aggressiveness of adult male mice varying in their genetic disposition for aggressive behavior

This study examined whether adult male aggression is influenced by either visual or olfactory exposure in early postnatal life to brief episodes of aggression. Another focus of interest was the interplay between a genetic disposition for aggressive behavior and early exposure experiences. The subjects used in the study were male mice of the 49th generation of selection for high (Turku Aggressive, TA) and low (Turku Non-Aggressive, TNA) levels of aggressiveness. Moderately aggressive males of the parental strain (Normal, N) were also used. Subjects of each strain were exposed from 21 to 32 days of age to fighting males either behind a wire mesh or glass screen. Control subjects were isolated during the entire experimental period. At 90–100 days of age, each subjects was tested three times for its aggressiveness. Exposure to fighting males behind a wire mesh screen enhanced later aggressiveness of juvenile male mice. Juveniles exposed solely to visual cues were comparable to isolates, both groups showing less adult aggression. Early experience and the genetic disposition for aggression were correlated; TA males showing the greatest increase in aggressive behavior. The role of early olfactory learning is discussed. © 1993 Wiley-Liss, Inc.     

Known risk factors for violence predict 12-month-old infants' aggressiveness with peers

This study tested the hypothesis that 12-month-old infants' use of force against peers is associated with known risk factors for violence. We conducted a prospective longitudinal study, which included laboratory observations of firstborn British infants (N = 271) during simulated birthday parties. No gender differences in aggressiveness were observed. The infants' observed aggressiveness was significantly correlated with mothers' mood disorder during pregnancy and with mothers' history of conduct problems. Infants' observed aggressiveness was correlated with parents' ratings of infants' anger and aggression, which were also predicted by mothers' mood disorder and history of conduct problems. Our findings indicate that infants at risk for serious aggression can already be identified when the motor ability to use physical force first enters the human repertoire.     

Pain cues and uncertainity as determinants of aggression in a situation involving repeated instigation.

In contrast to the Buss aggression paradigm, a situation was employed in which subjects were given an expanded range of response options and were exposed to instigation throughout their response period. It was found that (a) despite these changes pain cues depressed aggressiveness in the present situation as they generally do in the Buss paradigm, but that this effect only occurred where the subjects' aggression was initially ineffective in changing their target's behavior; (b) situational uncertainity, which is minimal in a Buss-type situation, was related to aggressiveness; (c) subjects tended to match rather than attempt to control the responses of the target; and (d) the present paradigm is capable of isolating a personality variable related to overall aggressiveness. These data are discussed in terms of other recent paid cue studies that deviate from the standard Buss situation. Generally, the findings suggest the potential of increasing the range of situations in which aggression is studied.     

Examination of the effects of traditional and modern martial arts training on aggressiveness

This study addresses two issues associated with the relationship between martial arts training and aggressiveness. The first is a replication of two recent findings, that for students trained traditionally, length of training varies inversely with aggressiveness, whereas for students trained in a “modern” style, length of training and aggressiveness are related directly. Second, we examine two competing explanations for the findings above. One is the training hypothesis, which holds that elements present in traditional approaches to martial arts but absent in modern approaches act to reduce aggression levels of students. These may include meditation, philosophy, emphasis on the kata (the forms of combat), etc. The alternate hypothesis, selection, holds instead that these findings are artifactual, a result of differential mortality in a setting characterized by high drop-out rates. Two categories of students were interviewed: “movers,” students who had trained in more than one school, and “quitters,” students who had terminated their training, for any reason. These students were compared with “stayers” from an earlier study. Our results are consistent with the opposite effects of traditional and modern martial arts training on aggressiveness. Further, the data generally support the training hypothesis as against selection.     

Implicit and explicit personality: a test of a channeling hypothesis for aggressive behavior

D. G. Winter, O. P. John, A. J. Stewart, E. C. Klohnen, and L. E. Duncan (1998) proposed that self-beliefs about personality influence the channels through which people express their implicit motives. On the basis of this hypothesis, the authors predicted that self-beliefs about aggressiveness would influence the channel(s) through which people express their aggressive motive and the justification mechanisms they use to defend expression of this motive. For example, the authors predicted that people who were implicitly prepared to rationalize a desire to harm others would engage in (a) overt aggression if they viewed themselves as aggressive or (b) passive aggression if they viewed themselves as nonaggressive. The implicit aspects of aggressiveness were measured via conditional reasoning (L. R. James et al., 2005). Results based on intramural basketball players supported the channeling hypothesis.     

Force versus fury: Sex differences in the relationships among physical and psychological threat potential,the facial width‐to‐height ratio,and judgements of aggressiveness

Individuals with larger facial width‐to‐height ratios (FWHRs) are judged as more threatening, and engage in more threat‐related behavior, than do individuals with smaller FWHRs. Here we identified components of threat potential that are related to the FWHR. In Study 1, the FWHR was correlated positively with physical threat potential (bicep size) in women and with both physical and psychological (anger proneness) threat potential in men. Behavioral aggression was measured in a subset of these participants using the Point Subtraction Aggression Paradigm (costly aggression) and a Money Allocation Task (non‐costly aggression). Psychological (but not physical) threat potential predicted non‐costly aggression and physical (but not psychological) threat potential predicted costly aggression. In Study 2, a separate set of participants judged the anger proneness, strength, or aggressiveness of male participants photographed in Study 1. Participants’ judgements of all three characteristics were associated with the FWHR, and there were sex differences in how aggressiveness was conceptualized (for women, aggressiveness was associated with anger proneness, for men, aggressiveness was associated with strength). These results are consistent with the hypothesis that the FWHR may be an adaptation to cue the threat potential of men.

     

中学生攻击性发展特点的研究

本研究以823名中学生为被试,采用问卷法考察了7种类型攻击性的发展特点。结果发现:(1)自行编制的《中学生攻击性问卷》具有较高的信度和效度。(2)在攻击性的各个维度上,攻击性水平均呈现出随年级升高而逐渐增强的发展趋势。(3)在违反制度、言语攻击、身体攻击、恶意和疑心等维度上,男生的攻击性水平显著高于女生。(4)在违反制度和疑心两个维度上,重点校学生的攻击性水平显著高于普通校学生。     

Withdrawal,matching, withdrawal-matching,and variable-matching strategies in reducing attack-instigated aggression

Several studies have investigated strategies that a participant in dyadic aggression may use to reduce the aggression of the other participant. In one set of these studies the subject is instigated to aggression by an opponent who sets maximum shocks for the subject to receive during the first block of six trials. Following attack-instigation, opponents shift to withdrawal and matching strategies for 18 trials. The withdrawal strategy is an abrupt shift to the lowest levels of shock possible. The matching strategy is the exact matching by an opponent of the shock set by the subject on the previous trial. With these procedures the withdrawal strategy has been the most effective method to reduce aggression. These results led to the suggestion that the effectiveness of the withdrawal strategy may be due to immediate, unambiguous communication by the opponent of his willingness to reduce attack. This hypothesis was tested in the present study by creating a matching condition modified to include immediate, unambiguous communication of willingness to reduce attack. In this withdrawal-matching condition the opponent followed attack with two trials of the lowest levels of shock before shifting to a matching strategy. Although the withdrawal-matching strategy did not lead to shock settings that were significantly lower than the matching strategy, there was evidence that subjects interacting with withdrawal-matching opponents did reduce their shock settings from block 1 to block 4 more rapidly than subjects interacting with matching opponents. A variable matching strategy was also used to provide a more realistic analogy of matching in the mundane world. While subjects with variable-matching opponents also did not set shock levels during blocks 2, 3, and 4 that were significantly lower than the matching strategy, there was evidence that subjects in this condition reduced their shock levels more rapidly than subjects with matching opponents. Although the effects were not as strong as expected, the results do provide some support for the interpretation that the effectiveness of the withdrawal strategy may be due to unambiguous communication of willingness by the opponent to reduce his or her aggression. The effectiveness of the variable-matching strategy was attributed to interrupting the tendency of the subject and his or her opponent to match each other's responses. Consistent with earlier attack-instigated aggression studies, the withdrawal strategy in the present study led to a rapid reduction in aggression.     

Gender,the Perception of Aggression,and the Overestimation of Gender Bias

The purpose of this study was to investigate how the gender of aggressor, target, and observer influences the perception and evaluation of aggression. One hundred seventy-one university students (predominantly White) read 1 of 8 vignettes that described an aggressive act. The aggressor–target gender combinations and the aggressive act were varied. Data did not support the hypothesis that, because of the impact of gender stereotypes, participants would perceive more aggressiveness in men's aggression than in women's aggression. Participants rated women's aggression as more acceptable than men's aggression, and male participants considered the aggression more acceptable, apparently because they saw the act as less aggressive. In addition, participants estimated how most men/women would perceive and evaluate the aggression. Results suggest that people overestimate how biased others are toward members of their own gender.