The relation of prosocial behavior to the development of aggression and psychopathology

The development of prosocial behavior is traced from middle childhood to adulthood in a 22-year longitudinal study of 800 children first seen at age 8 and is compared to the development of aggression over the same period. Prosocial behavior and aggression seem to represent opposite ends of a single dimension of behavior since they are consistently negatively related to each other and relate in opposite ways to correlated variables both synchronously and over time. Both are stable forms of behavior with good predictability over the time span studied and both are related to the quality of the parent-child relationship. The most important deterrent to the development of antisocial behavior and the encouragement of prosocial behavior is probably a close identification between the child and his/her parents.     

Reactive and proactive aggression as meaningful distinctions at the variable and person level in primary school‐aged children

Reactive and proactive aggression is a dichotomous classification of aggression in adults and children. This distinction has been supported by a number of variable‐based and factor analytic studies. Due to high inter‐correlations, however, the reactive—proactive aggression distinction may not be entirely useful for understanding how group or individual aggressive behavior varies in children and adolescents. Drawing on a sample of primary school‐aged children (N = 242) aged 7–12 years, this study sought to determine whether reactive and proactive aggression could be distinguished at the variable‐level and the person‐level in children. Exploratory Factor Analysis of data from an aggression instrument measuring both functions and forms of aggression, found a two‐factor construct of aggression constituted by a reactive and proactive aggression factor. A person‐based analysis was then conducted after classifying children according to the presence of reactive and/or proactive aggression. Discriminant function analysis was used to discern whether classifications on the basis of aggression function produced meaningful distinctions in terms of antisocial traits and emotional valence and intensity measures. Two functions were identified which distinguished children with different combinations of reactive and proactive aggression. Reactive‐only aggressive children were defined primarily by high levels of impulsivity, while proactive‐only children were defined primarily by higher levels of antisocial traits. Children high in both types of aggression exhibited both the presence of antisocial traits and impulsivity. Contrary to recent findings, this suggests that differences in aggression functions remain meaningful at the person level in children. Implications for interventions are discussed.

     

The heritability of antisocial behavior: A meta-analysis of twin and adoption studies

In this paper, we describe a quantitative summary of 12 twin (n=3795 twin pairs and 3 adoption studies=338 adoptees) published since 1975 which provided 21 estimates of the heritability of antisocial behavior. Medium to large effect sizes were found for genetic influences across studies, with approximately 50% of the variance in measures of antisocial behavior attributable to genetic effects. Although effect sizes did not vary across different definitions of antisocial behavior (criminality, aggression, or antisocial personality), significantly larger estimates of genetic effect were found for severe manifestations of antisocial behavior. The importance of severity was further underscored by the significantly larger effects obtained in studies using clinic-referred samples compared to the effects obtained in studies using volunteer samples. Demographic characteristics of the samples did not influence effect sizes, although studies using more stringent methodology tended to find larger effects. These results must be interpreted in light of the small literature that was suitable for the meta-analysis due to numerous methodological limitations in existing studies.     

Maternal aggression in mice: The non-specific nature of the exteroceptive maintenance by young

Five hours of pup removal during early lactation (Postpartum Day 6) reduced maternal aggression in mice, while placement of the dam's entire litter (six pups) or a single pup behind a double wire mesh partition in the homecage maintained aggression at a level identical to that of mothers in direct contact with their young. When placed behind the partition, unfamiliar 6, 13, and 20-day-old pups, but not 30-day-old mice, maintained the behavior as effectively as the dam's own young. The relationship of the findings to communal rearing conditions in the mouse is discussed.     

Overt and covert antisocial behavior: Child and family characteristics among psychiatric inpatient children

The present study examined child and family characteristics associated with overt and covert antisocial child behaviors. Child psychiatric inpatients (N=258, ages 6–13) were identified as high in overt and/or covert antisocial behaviors (e.g., aggression and stealing, respectively) based on a structured parent interview measuring antisocial behavior. Children were classified into four groups derived from the factorial combination of level of overt (high vs. low) and covert (high vs. low) antisocial behaviors. Analyses were made of the children's reactions to hostile and anger-provoking situations, deviant and prosocial child behaviors at home and at school, and family structure and organization. Children higher in overt antisocial behaviors were more negative, resentful, and irritable in their reactions to hostile situations and more aggressive at school. They came from families with significantly greater conflict and less independence among family members. Children higher in covert antisocial behavior participated in fewer social activities and were higher in anxiety; their families showed significantly lower family cohesion and organization and less of an emphasis on moral-religious values. The results suggest reliable differences in child and family functioning as a function of patterns of overt and covert antisocial behavior.     

Categories of behavior and the ontogeny of aggression

The papers in this symposiwn constitute important contributions to the study of children's aggression. Rather than summarizing them, it may be helpful in conclusion to underline two difficulties in understanding the ontogeny of aggression. Both are implicit in much of the symposium, and may in fact stem from the scientific methodology necessarily used to study behavior.     

The effects of two response-elimination procedures on reinforced and induced aggression.

Pecks against a stuffed pigeon were reinforced according to a fixed-interval schedule for one group of pigeons and a variable-interval schedule for a second group. Red and green stimulus lights were alternately illuminated. Subsequently, food deliveries no longer occurred during one color (extinction). In the presence of the other color, food was presented only when no attack occurred for 30 sec. When attack produced food, all pigeons generally exhibited characteristic fixed-interval or variable-interval response patterns. Two birds in each group frequently exhibited postreinforcement schedule-induced aggression. Attack was reduced to low levels at approximately the same rate by extinction and differential reinforcement of other behavior. For birds that had previously exhibited schedule-induced aggression the initial reduction of attack during the second experimental phase was followed by induced attack immediately after food delivery in the differential-reinforcement-of-other-behavior component and upon onset of the extinction component, Either extinction or differential reinforcement of other behavior may eliminate reinforced aggression but may be relatively ineffective for reducing induced attack.     

Interpersonal Relationships and Sex Differences in the Development of Conduct Problems

This article investigates the role of interpersonal relationships in shaping sex differences in the manifestation, etiology, and developmental course of conduct problems and their treatment needs. The review examines whether: (1) Girls conduct problems are more likely than boys to manifest as a function of disrupted relationships with caretakers and peers; (2) For girls more than for boys, the outcomes of conduct problems in adolescence and adulthood, and related treatment needs, are more likely to be a consequence of the quality of interpersonal relationships with others, particularly opposite-sex peers and partners. Evidence reviewed suggests that boys and girls share many similarities in their expression of conduct problems, but that a relational perspective does unify important differences. There is fair evidence that girls with conduct problems are more likely to come to the attention of authorities because of chaotic, unstable family relationships, and to express antisocial behavior in the context of close relationships; there is stronger evidence that the course and outcomes of conduct problems in females versus males pertain to interpersonal relationship impairments. Those sex differences map onto specific differences in treatment needs. Further empirical testing of the proposed relational model is indicated.     

Behavioral tactics control the energy costs of aggression: The example of Macropodus opercularis

Previous experiments on Betta splendens have shown that energy expenditures related to aggression are under social control. The present paper examines the biochemical energetics of social cohabitation in groups of Macropodus opercularis. The species is closely related to Betta splendens, however, dominants use somewhat different behavioral tactics against intruders. In contrast to Bettas, submissive Macropoduses are not harassed by dominants, but are confined to the bottom of the tank. This results in a reduced rate of oxygen consumption in defeated animals (Anabantid fish mainly use atmospheric oxygen). The only metabolic change, compared to isolated controls, is a reduction in hepatic glycogen content. Submissive animals have shifted carbohydrate metabolism towards anaerobic glycolysis. Substantial reductions in muscle proteins, lipids, and glycogen occurred in submissive Betta splendens. Thus, the sharp difference in behavioral strategy results in a sharp difference in the energetic consequences of aggression. A theory is presented regarding the possible role of energetic constraints in the control of behavior. © 1996 Wiley-Liss, Inc.     

On the dual nature of maternal aggression in rats

Presentation of a natural predator, a cat, was used to differentiate elements of maternal attack by female rats on a male intruder. Following exposure (without direct physical contact) of post-partum females to a cat or to a toy stuffed cat (control group), the females were replaced in their home cages and presented with a male intruder rat. Cat exposure reliably decreased lateral attack to the intruder, as well as locomotion, but had no effect on either jump attack or an upright defensive posture (boxing). Since predator exposure produces a somewhat durable increase in defense, along with inhibition of nondefensive behavior, these results suggest that maternal aggression represents a mixture of offensive, usually related to competition, and defensive (protective) behaviors. The results indicate that maternal aggression, as a parental care behavior, appears to be at least partially resistant to fear. © 1996 Wiley-Liss, Inc.     

Maternal aggression in mice: Protection of young is a by-product of attacks at the home site

Lactating female mice attacked male intruders in their home cages but showed little attack behavior either in novel cages or in cages with which they had been familiarized. Presence or absence of young did not determine the occurrence of maternal aggression, whereas attacks on the young by the intruder decreased maternal aggression and increased cannibalism of pups by the dams. Apparently, if the function of maternal aggression in mice is protection of the young, such protection occurs because the pups are in a place where attacks are likely to occur and not because the dam “defends” the young.     

Attack-target attributes and pigeon aggression: Accessibility,vocalization, and body movements

Characteristics of the attack-target in laboratory tests appear to greatly influence the tendency for aggression to be initiated, maintained, and stopped. To address this question, accessibility, target movement, and vocalization among pigeon conspecifics were investigated in two different aggression tests: 1) paired aggression (PA); and 2) schedule-induced aggression (SI). In the PA test, dominant and subordinate roles formed quickly, and soon aggression episodes started to decline. In part, the subordinate's yielding behavior appeared to discourage attack. The significance of the target bird's behavior on attack frequency was borne out by the finding in the SI test that pigeons attacked a shielded, live, active target more often than a passive one. Furthermore, using a specially constructed stuffed pigeon in the SI test, results indicated that programmed, combined aggressive vocalization and body movement evoked most attacks with the VT schedule, vocalization alone evoked the next highest number of attacks, body movement alone the third most, and combined silence and immobility the least attacks. These findings provide a basis for explaining some past reported results associated with target features and a means for selecting other target features for future study.     

Maternal aggression as a model for acute social stress in the rat: A behavioral-electrocardiographic study

Maternal aggression of lactating rats was used to induce acute social stress in a resident-intruder paradigm. Behavioral and electrocardiographic responses of male intruders were simultaneously recorded. Cardiac electrical activity was measured by means of a telemetry system which ensured preservation of intruder's behavioral repertoire. Behavioral response to maternal attack was evaluated in terms of percent time spent in passive/submissive (p/s) and active/non-submissive (a/ns) patterns. This allowed us to classify the intruders as submissive, non-submissive, and intermediates. During the test, a significant decrease of average R-R interval (R-R) compared to baseline conditions and the occurrence of arrythmias of different nature were found. Ventricular arrhythmias, including premature ventricular beats and ventricular tachycardias, were present in all the intruders while R-R fluctuations and II degree atrioventricular (A-V) blocks only appeared in submissive and intermediate rats. Most ventricular arrhythmias occurred within the upper range of heart rate and were preceded by periods of low R-R variability. These electrocardiographic events were temporally associated with a/ns behavioral patterns and were related to an increased prevalence of sympathetic activity. On the other hand, R-R fluctuations and II degree A-V blocks preceded by high R-R variability were synchronized with p/s behavior and were ascribed to a predominant inhibitory effect of vagal activation which becomes more pronounced as the level of sympathetic activity increases. © 1995 Wiley-Liss, Inc.     

Agreeableness as a predictor of aggression in adolescence

This multi‐method research linked the Big Five personality dimensions to aggression in early adolescence. Agreeableness was the personality dimension of focus because this dimension is associated with motives to maintain positive interpersonal relations. In two studies, middle school children were assessed on the Big Five domains of personality. Study 1 showed that agreeableness was associated with both indirect and direct aggression. In addition, the link between agreeableness and aggression was strongest for direct strategies. Study 2 examined the hypotheses that agreeableness predicts social cognitions associated with aggression, peer reports of direct aggression, and teacher reports of adjustment. Agreeableness predicted peer reports of aggression and social cognitions associated with aggression. In addition, aggression mediated the link between agreeableness and adjustment. Results suggest that of the Big Five dimensions, Agreeableness is most closely associated with processes and outcomes related to aggression in adolescents. Aggr. Behav. 30:43–61, 2004. © 2004 Wiley‐Liss, Inc.     

Subfactors of DSM-IV Conduct Disorder: Evidence and Connections with Syndromes from the Child Behavior Checklist

Is conduct disorder (CD) as defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV; American Psychiatric Association, 1994) a unitary entity, or do variants of CD exist? We addressed this question, using data collected from the parents of 1,669 Australian boys, aged 6–17. Parents were interviewed to assess DSM-IV Conduct Disorder (DSM-IV CD) criteria. Results revealed 2 subfactors of DSM-IV CD symptoms, made up of overt behaviors (e.g., initiating physical fights) and covert behaviors (e.g., stealing without confrontation). Ordinary least squares regressions showed the 2 CD subfactors to be significantly and uniquely predicted by Child Behavior Checklist (CBCL; T. M. Achenbach, 1991a, 1991b) syndromes labeled Aggressive Behavior and Delinquent Behavior, respectively. The results are discussed in terms of the utility of differentiating these 2 variants of CD in future editions of the DSM.     

The effects of viewing physical and relational aggression in the media: Evidence for a cross-over effect

Research has shown that viewing violence in the media can have a profound impact on aggressive thoughts and behaviors. However, the impact of viewing relational aggression in the media has rarely been examined. This paper presents the results of an experimental study that examines the impact of viewing relational and physical aggression in the media on subsequent aggression. In this study, adult females were shown video clips containing no-aggression, relational aggression, or physical aggression. Their aggressive behavior was measured through the use of a competitive reaction time task (physical aggression) and evaluations of a confederate of the experiment (relational aggression). As a whole, participants viewing either relational or physical aggression behaved similarly. Specifically, participants who viewed either type of aggression were subsequently more physically and relationally aggressive than those who viewed the non-aggressive clip. The results show evidence for a generalization effect of viewing media aggression, in that viewing one form of aggression can influence the manifestation of other forms. This is the first study to show that viewing relational aggression in the media can increase subsequent physical aggression. Implications for parents, media producers, and policy makers are discussed.     

The expression of the genes of aggressiveness in mice: The effect of androgen on aggression and sexual behavior in females

Female mice of strains selectively bred for aggressiveness or nonaggressiveness were injected with testosterone propionate (TF′) at the age of 2 days and as adults, or they were injected as adults only. Aggressive and sexual behavior was then tested with female, receptive female, and male partners before, during, and after the latter TP treatment. The females that had received both TP treatments displayed as much or as little aggression as males of the same strain, leading to the conclusion that aggressiveness genes are not linked with the male sex chromosome, even though they depend on it for their expression. The sexual behavior of the females of both strains that had received both TP treatments was altered to the male type. In the females of the aggressive strain even adult treatment alone was sufficient for this change. Aggressiveness and male sexual behavior would seem to be determined separately, although aggressiveness facilitates the display of male sexual behavior.     

Involvement of amygdala in inhibitory control over aggression in the rat: A synopsis

An experimentally produced hyperreactivity facilitates initiation of mouse-killing in rats that did not previously develop any stable inhibition of interspecific aggression. Destruction of the corticomedial amygdala or interruption of the stria terminalis interferes with the development of such an inhibition on the basis of “social” influences, whereas lateral amygdaloid lesions have no effect on mouse-killing.