Psychological aggression predicts physical aggression in early marriage.

Psychological aggression by self and partner, physical aggression by the partner, and marital dissatisfaction were examined as longitudinal predictors of first instances of physical aggression during marriage. Subjects who were not physically aggressive at a premarital assessment were selected from a sample of 393 engaged couples. Couples participated in three subsequent assessments over the first 30 months of marriage. As hypothesized, individuals' own psychological aggression predicted their initial incidents of physical aggression in marriage. Psychological aggression by their partners also predicted initial incidents of physical aggression. Prior physical aggression by their partners was inconsistently associated with first instances of physical aggression. Contrary to our hypothesis, previous levels of marital dissatisfaction did not predict initial incidents of physical aggression. These findings were consistent across sexes. The results underscore the progression from psychological to physical abuse and have clear implications for understanding the development and prevention of interspousal aggression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Components of aggression in chickens and conceptualizations of aggression in general.

A refined analysis of the peck order in chickens is offered as a test of the notion that, for this species, different responses such as leaping and various types of pecking need not be interchangeable indexes of aggression. Tests showed that particular response types of the birds were differentially mediated by organismic or environmental factors. 36 pairs of male and female White Leghorn chicks were assigned to large cages, and 48 pairs were assigned to small cages. In large cages pecking at the body was most frequent by Ss that had a home-cage advantage. Contrarily, rates of aggressive leaping were independent of this influence, with males having an advantage over females. Males showed more head pecking than females, but the profile for this sex difference did not resemble the profile for leaping. Correlational analyses revealed that whereas head pecking between testmates was not matched in frequency, leaping was positively related. The behavior of Ss in small cages differed from that of large-cage Ss. Although there was more head pecking in small cages, males did not have an edge, and leaping was infrequent. Results indicate that these responses cannot be viewed as interchangeable indicators of aggression in fowl. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Maternal permissiveness toward aggression and subsequent TAT aggression.

To test the hypothesis that the effect of permissiveness towards the expression of aggression in childhood extends into adulthood, 2 groups of Ss (100 college girls), distinguished by the degree of maternal permissiveness towards the expression of aggression (derived from questionnaires answered by the mothers), were placed in an aggression-arousing situation (inducted by making highly insulting and deprecating comments to them). Subsequently, Ss were asked to respond to TAT cards (selected on the basis of being high or low in aggressiveness and presented on a screen for 20 sec.). Ss reared under conditions of high maternal permissiveness responded more frequently with aggressive responses to the "aggressive" cards than did the low permissive group. The low permissive group felt more uncomfortable and dysphoric than Ss reared under conditions of greater permissiveness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of positive reinforcement of aggression on subjects differing in initial aggression level.

60 females, who were ostensibly serving as assistants in a learning study, were required to deliver electric shocks as punishments for "errors" to a confederate of E. Ss selected the intensity of the shock they delivered. During a training period experimental Ss were verbally reinforced for delivering shocks of relatively high intensity. Pretest-to-posttest increases in intensity of shock were significantly greater for experimental Ss than for control, nonreinforced, Ss. This increase was, however, confined to Ss who used an intially high or medium level of intensity; Ss initially using low initial intensities were not influenced by the reinforcement procedure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Censure of vicarious aggression as an instigation to subsequent aggression.

Presented a taped dialogue between a black man and an insulting white man to 89 undergraduates. Eventually the black man reacted with aggression, and the 80 Ss endorsing his actions were retained. Ss then heard 1 of 3 taped commentaries-censure, neutral, and justification-and made a number of ratings. Censure significantly increased the aggression measure over the neutral commentary and was slightly higher than justification. The main target of aggression was the commentator who delivered the censure communication. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Human aggression in evolutionary psychological perspective

This article proposes an evolutionary psychological account of human aggression. The psychological mechanisms underlying aggression are hypothesized to be context-sensitive solutions to particular adaptive problems of social living. Seven adaptive problems are proposed for which aggression might have evolved as a solution--co-opting the resources of others, defending against attack, inflicting costs on same-sex rivals, negotiating status and power hierarchies, deterring rivals from future aggression, deterring mates from sexual infidelity, and reducing resources expended on genetically unrelated children. We outline several of the contexts in which humans confront these adaptive problems and the evolutionary logic of why men are cross-culturally more violently aggressive than women in particular contexts. The article concludes with a limited review of the empirical evidence surrounding each of the seven hypothesized functions of aggression and discusses the status and limitations of the current evolutionary psychological account.     

Violence and aggression in psychiatric units

OBJECTIVE: To help predict aggressive and violent behaviors, the frequency and types of these behaviors in acute psychiatric inpatient settings were examined, and potential interactions between staffing and patient mix and rates of the behaviors were explored. METHODS: Data on violent incidents were gathered prospectively in three adult acute psychiatric units in a general hospital and two units in a primary psychiatric hospital in Sydney, Australia. Staff recorded violent and aggressive incidents, which were ranked on an 8-level scale. They also completed weekly reports of staffing levels and patient mix. Poisson regression analysis was used to calculate relative rates, 95 percent confidence intervals, and p values. RESULTS: A total of 1,289 violent incidents were recorded over a seven-month period. Based on the scale, 58 percent of the incidents were serious. Seventy-eight percent were directed toward nursing staff. Complex relationships between staffing, patient mix, and violence were found. Relative risk increased with more nursing staff (of either sex), more nonnursing staff on planned leave, more patients known to instigate violence, a greater number of disoriented patients, more patients detained compulsorily, and more use of seclusion. The relative risk decreased with more young staff (under 30 years old), more nursing staff with unplanned absenteeism, more admissions, and more patients with substance abuse or physical illness. In total these factors accounted for 62 percent of the variance in violence. CONCLUSIONS: Violent incidents in psychiatric settings are a frequent and serious problem. Incidents appear to be underreported, and the seriousness of an incident does not guarantee it will be reported.     

Interspecific aggression in wild mice.

Determined probabilities of interspecific fighting and relative dominance status between Mus musculus and various species of Peromyscus mice in laboratory encounters. It was felt that interspecific dominance as measured by encounter outcomes might contribute to determination of species survival. Species differences in social and nonsocial behaviors were analyzed for whether differences were caused by real behavioral differences between the species, or by behavioral differences between dominant and subordinate animals of any species. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement of aggression in psychiatric patients

We have used representational difference analysis (RDA) for subtractive hybridization of oligo dT primed directionally cloned cDNA libraries from human inner ear tissue and a B-lymphoblast cell line. Two rounds of subtraction-amplification, followed by differential hybridization of selected clones led to the isolation of genes which were specific to the ear. Sequence analysis of randomly chosen clones revealed the presence of a histidine rich Ca2+ binding protein, human dynamin, collagen type 1A1, collagen type 2A1, SPARC, human growth hormone, and several specific genes which had no sequence homology in the data base. Furthermore, to apply these techniques for isolating genes specific to distinct inner ear structures and/or cell types of inner ear for which the starting tissue material is limiting, we have used a modified PCR based protocol to construct representative cDNA libraries. We have characterized a cDNA library constructed from small amounts of inner ear tissues recovered by ablative surgical procedure involving labyrinthectomy. The potential application of these protocols for isolating genes involved in hearing and deafness is discussed.     

Displaced aggression in young children.

Young children played a card game in which some Ss associated losses with a child-figure card and winnings with a plain card, while others associated losses with a plain card and winnings with the child-figure card. Following the card game, Ss played a shooting game in which they selected targets from among pairs of figures that varied from the card game figure on a dimension of physical similarity. Both sexes showed a significant tendency to select, as targets, either figures more like or figures less like the card game figure. There were no differences in target choices as a function of conditions. Among Ss who lost to the card game figure, boys and girls differed, boys favoring more like figures and girls favoring less like figures. The Ss also shot the card game figure itself. Boys who lost the most to that figure shot the greatest number of times; those who lost less, the fewest numbers of times; and boys who won from the figure were in between. No differences were found for girls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuropharmacology of brain-stimulation-evoked aggression

Evidence is reviewed concerning the brain areas and neurotransmitters involved in aggressive behavior in the cat and rodent. In the cat, two distinct neural circuits involving the hypothalamus and PAG subserve two different kinds of aggression: defensive rage and predatory (quiet-biting) attack. The roles played by the neurotransmitters serotonin, GABA, glutamate, opioids, cholecystokinin, substance P, norepinephrine, dopamine, and acetylcholine in the modulation and expression of aggression are discussed. For the rat, a single area, largely coincident with the intermediate hypothalamic area, is crucial for the expression of attack; variations in the rat attack response in natural settings are due largely to environmental variables. Experimental evidence emphasizing the roles of serotonin and GABA in modulating hypothalamically evoked attack in the rat is discussed. It is concluded that significant progress has been made concerning our knowledge of the circuitry underlying the neural basis of aggression. Although new and important insights have been made concerning neurotransmitter regulation of aggressive behavior, wide gaps in our knowledge remain.     

Forms of juvenile aggression

Delinquent behaviour has its roots in early childhood: Hyperactivity and impulsivity are its precursors, especially if rules are not clearly set in kindergarten and school and if aggressive behaviour is tolerated. Conduct disorders are classified into several subgroups with different treatment strategies. Epidemiologically there is no evidence of an increase of aggression and delinquency in childhood and adolescence. As only a small portion of children and adolescents with aggression and conduct problems are considered to be in need of treatment by their parents, early and intensive intervention is necessary.     

Creativity and aggression.

We studied problems of identification in an experiment using a meta-contrast design. The first stimulus in the pair (A) was the word I shown subliminally. The second stimulus (B) depicted an aggressor and a victim facing each other. To manipulate the subject's identification, the subliminal A was flashed either on the victim or on the aggressor, or was completely withheld. Subjects were 28 16-year-olds of both sexes. They also took a perceptgenetic (PG) test measuring creativity and a test on anxiety and defensive strategies as revealed in the perceptual process (the meta-contrast technique or MCT). It was predicted that creative subjects would identify more openly with the aggressor than noncreative ones, when I was presented on the aggressor. Differences in the use of defenses were also expected. The results supported the predictions. It was concluded that creative subjects are more self-reliant than noncreative ones, more inclined to believe in the value of private impressions and ideas. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generalization effects of coping-skills training: Influence of self-defense training on women's efficacy beliefs, assertiveness, and aggression.

Concern for personal safety is a pervasive stressor for many women. Developing competencies in physical self-defense may empower women to engage more freely in daily activities with less fear. This study assessed the effects of physical self-defense training on multiple aspects of women's perceived self-efficacy and other self-reported personality characteristics. Training powerfully increased task-specific (self-defense) efficacy beliefs as well as physical and global efficacy beliefs. Training increased self-reported assertiveness, and posttraining decreases in hostility and aggression were found on several of the subscales of The Aggression Questionnaire (A. H. Buss & M. Perry, 1992), indicating that training did not have an aggression-disinhibiting effect. In the experimental condition, most of the effects were maintained (and some delayed effects appeared at follow-up. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Copulation and intermale aggression in rats.

Exp I observed attack behavior of 9 reliably aggressive male Long-Evans rats against unfamiliar male intruders immediately following copulation to one or more ejaculations. Copulatory series to 5 ejaculations did not differ from copulation to a single ejaculation or from a noncopulatory control in affecting aggressive behavior. Repetitive biting attacks occurred in all conditions, with comparable wounding. Evidently, the male postejaculatory state of insensitivity to sexual stimuli does not extend to stimuli eliciting intermale aggression. A 2nd experiment determined the attack-eliciting capacity of foreign males placed in the home cage of an actively copulating S. As intromissions increased and the interval to ejaculation decreased, the probability of intermale aggression and interruption of copulation diminished. Findings suggest that a postejaculatory mechanism for behavioral inhibition exists in the male rat, preventing his interference with fertilization but without affecting his capacity to prevent other males from attempting to displace the fruits of his labors. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Isolation-induced aggression in newly hatched ducklings.

Describes 3 experiments with a total of 40 Khaki Campbell ducklings. In Exp I newly hatched Ss were initially housed in pairs and subsequently transferred to isolated housing conditions. Ss living with another bird displayed filial behavior and little aggression upon encountering another duckling in a test arena. In contrast, Ss housed in isolation exhibited aggressive pecking in addition to filial behavior when another duckling was subsequently encountered. In Exp II, Ss were housed with an imprinting object (i.e., an object that elicits attachment behavior) but were otherwise isolated from other birds. These Ss displayed little aggression when they were subsequently reunited with a conspecific, indicating that the aggression-precluding effects of social housing are not limited to the particular social stimulus with which the ducklings are housed. In Exp III, Ss were again housed with an imprinting object, but this time the object was behind glass, thereby precluding tactile contact with it. Since these Ss also exhibited little aggression when reunited with a conspecific, it is apparent that visual stimulation from an imprinting object is sufficient in itself to preclude subsequent aggression. Findings suggest that stimulation that elicits attachment behavior is the critical factor mediating isolation-induced aggression. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relational and overt aggression in preschool.

This research was designed as an initial attempt to assess relational aggression in preschool-age children. Our goal was to develop reliable measures of relational aggression for young children and to use these instruments to address several important issues (e.g., the relation between this form of aggression and social–psychological adjustment). Results provide evidence that relationally aggressive behaviors appear in children's behavioral repertoires at relatively young ages, and that these behaviors can be reliably distinguished from overtly aggressive behaviors in preschool-age children. Further, findings indicate that preschool girls are significantly more relationally aggressive and less overtly aggressive than preschool boys. Finally, results show that relational aggression is significantly related to social–psychological maladjustment (e.g., peer rejection) for both boys and girls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conspecific aggression in the laboratory rat.

In 2 experiments, attacks by dominant colony males of a domesticated rat strain (Sprague-Dawley; N = 48) on conspecific strangers introduced into the colony included both a full range of threat displays and actual biting attack. These dominant males attacked and bit both anesthetized and unanesthetized strangers, but threat displays and bites to anesthetized rats were limited. Lesions resulting from these bites were 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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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.