Stages in the development of aggressive behavior in early childhood

Primary manifestations of aggression appear in the behavior of children in the second half of the first year of life. The frequency of Occurrence of interpeer aggression increases with age, and reaches its maximum in the third year. The frequency of aggression may later decrease, but there are considerable individual differences. Changes a h Occur in the form in which aggression is manifested; its motivational background and associated elicitors; its direction, duration, timing, and other operational characteristics, and in the modes of its acquisition. A certain continuity may be traced, however, in any of these features and the development of aggression may be perhaps more adequately represented by the following sequence of developmental stage:

• 1 Stage of preaggressive behavior;
• 2 Stage of primary differentiation;
• 3 Stage of the appearance of the individual pattern of aggressive behavior;
• 4 Stage of secondary differentiation of aggression;
• 5 Stage of the beginning of the transition into covert behavior—internalization of aggression

These stages represent certain facets of the interaction between the changing behavioral performance of the child and herlhis social environment, and may be used for evaluating aggressive behavior in young children.     

Gender-specific social experiences and the development of aggressive and sexual behavior in male mice

This study examined influences of gender-specific social experiences on the development of aggressive and sexual behavior in male mice. To determine the effects of gender-specific social experience three different types of groups were constituted after the animals had been weaned. The subjects were randomly assigned to different treatments. Female groups were composed of one experimental male and three female cohabitants. Male groups were composed of five experimental males each, and the mixed-sex groups were composed of two experimental males and of two females. The experimental subjects stayed in these groups until the age of approximately three months, when the testing for sexual and aggressive behavior commenced. For the sexuality tests, a receptive female was placed in the home cage of the experimental male for ten minutes. A nonaggressive male was placed in the home cage of the experimental male for seven minutes for the aggression tests. The experimental males were administered both sexuality and aggression tests, the sequence of testing sexual and aggressive behavior was systematically varied in order to control the influence of the two different types of behavioral tests. The results showed that males with only male social experiences showed fewer responses and were less active in both the aggression and sexuality tests than the males from the two other types of groups. Significant positive correlations between activity during aggression and sexual tests were obtained for all three groups. © 1994 Wiley-Liss, Inc.     

Exogenous testosterone and social experience each enhance the development of aggressive behavior in Cyprinodon variegatus

The combined effects of testosterone and social experience from the time of hatching on development of aggressive behaviors in Cyprinodon variegatus were investigated. Social experience was defined as a rearing condition allowing visual, tactile, chemosensory, and auditory contact with zero, three, or 15 additional conspecifics. Behaviors were videotaped once weekly from 3 weeks to 4 months post-hatching, using the focal animal method, and an ethogram was constructed. At 3 months post-hatching, half the fish were injected once with testosterone propionate (2 μg/g b. w., i. p., vehicle-Ringer's solution) and the other half were injected with Ringer's isotonic saline solution. Testosteronetreated subjects showed significantly greater frequencies and durations of behaviors that may be related to aggression than did saline controls. Two weeks after the treatments, a round-robin tournament was conducted between testosterone- and saline-treated fish from each rearing condition. Testosterone-treated fish won significantly more encounters than did saline-treated subjects over all rearing conditions. Furthermore, significantly more aggressive acts were displayed by fish raised in the groups of 16 and the groups of four than did the Isolates. Although the number of aggressive acts exhibited by the group of 16 was greater than the group of four, the difference was not statistically significant.     

A social identity approach to explaining children's aggressive intentions

This study explored the effects of group norms, intra-group position, and age on the direct and indirect aggressive intentions of 247 children (aged 5.50 to 11.83 years). Participants were assigned to a team, with team norms (aggression vs. helping) and the child's position within the team (prototypical vs. peripheral–prototypical vs. peripheral) manipulated. Results showed that children in the aggressive norm condition reported greater aggressive intentions than those in the helping norm condition, although, when age was considered, this effect remained evident for younger, but not older, children. Similarly, intra-group position influenced the aggressive intentions of younger children only. For these children, when group norms supported aggression, prototypical members and peripheral members who anticipated a future prototypical position reported greater aggressive intentions than peripheral members who were given no information about their future position. The implications of these findings for understanding childhood aggression, and for intervention, are discussed.     

Effects of reactivity to dorsal stimulation and social role on aggressive behavior in laboratory rats

Rats were selected on the basis of reactivity to dorsal tactile stimulation and then tested in a resident-intruder paradigm. While reactivity of residents did not influence the occurrence of agonistic behaviors or wounding of residents and intruders, reactivity of intruders did affect offensive and defensive patterns of interactions and the wounds sustained by residents and intruders. Subsequent to resident-intruder testing, rats were tested for shock-induced aggression. The pattern of the results and the results of additional experiments demonstrated that resident-intruder experience could affect subsequent shock-induced aggressive behavior.     

A 3-Year follow-up of aggressive and withdrawn behavior in childhood: Preliminary findings

The school placement of 122 aggressive, 150 withdrawn, 182 aggressive-withdrawn, and 299 control children was determined 3 years following their original selection. Children identified by peers as aggressive-withdrawn or aggressive were more likely to have failed a grade or to be in a special class than were withdrawn children or controls. Older aggressive-withdrawn subjects and controls, but not aggressive subjects or withdrawn subjects, had higher rates of school failure and special class placement. Fewer boys than girls were in a regular class at the expected grade level. The results underline the importance of childhood aggression as a predictor of later academic adjustment. Implications of these findings for the interpretation of measures of behavioral stability are discussed.The research reported here was supported by Quebec Ministry of Social Affairs Grant RS 281 to Jane Ledingham and Alex Schwartzman. The authors would like to thank the Commission des Ecoles Catholiques de Montréal for their continuing cooperation in this project, and Debbie Moskowitz and Alastair Younger for their constructive comments on an earlier draft.     

Adolescents' aggressive and prosocial behavior: associations with jealousy and social anxiety

The authors examined how relational aggression, physical aggression, and proactive prosocial behavior were associated with jealousy and social anxiety in a diverse sample of 60 middle school students. After the authors controlled for gender and race, jealousy predicted relational aggression and proactive prosocial behavior, but it did not predict physical aggression. Additionally, social anxiety predicted proactive prosocial behavior. Adolescents who were more jealous in their peer relationships also tended to engage in relational aggression and proactive prosocial behavior, and adolescents who were more socially anxious also tended to be proactively prosocial. The authors discuss the implications of these findings and suggest directions for future research.     

Toward an integrated approach to early childhood stuttering

This article proposes a model that integrates various factors influencing early childhood stuttering. The factors interact in a synergistic manner and can be subsumed under three macrofactors: physiological, psycholinguistic, and psychosocial. Such a model can be clinically applied toward an integrated approach to the assessment and treatment of the young stutterer.     

Further tests of an exemplar-similarity approach to relating identification and categorization

Further tests were provided of an exemplar-similarity model for relating the identification and categorization of separable-dimension stimuli (Nosofsky, 1986). On the basis of confusion errors in an identification paradigm, a multidimensional scaling (MDS) solution was derived for a set of 16 separable-dimension stimuli. This MDS solution was then used in conjunction with the exemplar-similarity model to accurately predict performance in four separate categorization paradigms with the same stimuli. A key to achieving the accurate quantitative fits was the assumption that a selective attention process systematically modifies similarities among exemplars across different category structures. The tests reported go well beyond earlier ones (Nosofsky, 1986) in demonstrating the generalizability and utility of the theoretical approach. Implications of the results for alternative quantitative models of classification performance, including Ashby and Perrin's (1988) general recognition theory, were also considered.     

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 conditional approach to dispositional constructs: the local predictability of social behavior

A conditional approach to dispositions is developed in which dispositional constructs are viewed as clusters of if-then propositions. These propositions summarize contingencies between categories of conditions and categories of behavior rather than generalized response tendencies. A fundamental unit for investigating dispositions is therefore the conditional frequency of acts that are central to a given behavior category in circumscribed situations, not the overall frequency of behaviors. In an empirical application of the model, we examine how people's dispositional judgments are linked to extensive observations of targets' behavior in a range of natural social situations. We identify categories of these social situations in which targets' behavior may be best predicted from observers' dispositional judgements, focusing on the domains of aggression and withdrawal. One such category consists of subjectively demanding or stressful situations that tax people's performance competencies. As expected, children judged to be aggressive or withdrawn were variable across situations in dispositionally relevant behaviors, but they diverged into relatively predictable aggressive and withdrawn actions in situations that required the social, self-regulatory, and cognitive competencies they lacked. Implications of the conditional approach for personality assessment and person perception research are considered.