Effects of prior social experience on agonistic responding by Siamese fighting fish (Betta splendens)

The role of prior social experience in maleBetta agonistic behavior was investigated in two experiments. Fish were either paired with an opponent until dominance was established naturally (Experiment 1) or given prior combat experience with a known aggressive or nonaggressive opponent (Experiment 2). The effects of prior social experience were then observed both in additional paired encounters and in some noncombat agonistic situations. The paired-encounter data indicate thatBetta attack aggressive opponents more than nonaggressive ones and rarely attack opponents once they have submitted. In contrast to attacking, these fish do not show a significant decrease in displays once their opponent has submitted, nor do they display differentially to aggressive and nonaggressive opponents. The noncombat agonistic-situation data indicate that prior social experience affects both the preference of fish for viewing other conspecifics and the waning of display behaviors. These results suggest that submissive and nonaggressive behaviors can inhibit attacks but not displays byBetta, and they emphasize the necessity of controlling for prior social experience when studying aggressive behavior.     

Social organization and the maintenance of aggressive behavior in community-housed male Siamese fighting fish (Betta splendens)

The waning of aggressive behavior in two groups of community-housed maleBetta was studied by observing incidences of display and fighting behaviors. In Experiment 1, observations were made during the establishment of a community, while it was maintained at a stable size, and during systematic removal of the dominant (alpha) males. Experiment 2 investigated the aggressive interactions of males in a stable-sized population, maintained for a period of 10 weeks. The results indicate that prolonged periods of constant conspecific exposure do not necessarily result in a significant attenuation of display behaviors. The data further indicate that the social organization (as determined from aggressive interactions) appears to be one in which the top- and bottom-ranking males are clearly defined. It is suggested that the maintenance of aggressive behavior among community-housed maleBetta may well be related to their social position.     

Territorial behavior of laboratory rats under conditions of peripheral anosmia

Two experiments investigated the influence of peripheral anosmia with zinc sulfate solution on aggressive and nonaggressive behaviors of rats in the colony intrusion paradigm. Experiment I was a replication of a previous observation that anosmic intruders arenot attacked by resident males. No significant differences were found in aggressive response to normal or anosmic intruders. Experiment II tested colony residents under normal and anosmic conditions for aggressive and nonaggressive response to intruders. The results were in agreement with previous reports that anosmia abolishes differential responding between males and females as well as all aggressive acts normally directed against unfamiliar males.     

Effects of habituation on threat display and dominance establishment in the Siamese fighting fish,Betta splendens

In three separate experiments, maleBetta splendens were exposed, respectively, to mirror images, a variety of conspecifics, and to future opponents, prior to combat with unexposed subjects. Threat display to mirror images and to live opponents habituated significantly, but the outcomes of dominance-subordinance tests were not significantly affected by prior exposure to any of the threat-eliciting stimuli. Results are discussed in terms of stimulus and response specificity and possible chemical suppression of agonistic behavior.     

Sex differences in the etiology of aggressive and nonaggressive antisocial behavior: results from two twin studies

Recent theory and results from twin and adoption studies of children and adolescents suggest greater genetic influence on aggressive as compared to nonaggressive antisocial behavior. In addition, quantitative or qualitative differences in the etiology of these behaviors in males and females have been indicated in the literature. The Child Behavior Checklist was completed by the parents of 1022 Swedish twin pairs aged 7-9 years and of 501 British twin pairs aged 8-16 years. Genetic factors influenced aggressive antisocial behavior to a far greater extent than nonaggressive antisocial behavior, which was also significantly influenced by the shared environment. There was a significant sex difference in the etiology of nonaggressive antisocial behavior. Bivariate analyses supported the conclusion that the etiologies of aggressive and nonaggressive antisocial behavior differ for males and females.     

Influence of conspecific and predatory Stressors and their associated odors on defensive burying and freezing responses

In Experiment 1, male rats were exposed to either aggressive (i.e., alpha) or nonaggressive conspecific colonies and tested 24 h later, with or without alpha odors, for freezing behavior and burying of a wall prod that had been the source of a brief electric shock. The results indicated that prior defeat experience and the presence of alpha odors alone during testing had no significant effects, but the combination of prior defeat and alpha-odor testing significantly decreased burying and increased freezing behavior. In Experiment 2, we examined the effects of noncontact exposure to a cat, as a predatory Stressor, during subsequent prod-shock tests involving the presence or absence of cat odors. Exposure to a cat failed to disrupt later prod burying and did not produce freezing. However, the presence of cat odors during testing significantly reduced the amount of defensive burying,without resulting in an increment in freezing. In Experiment 3, rats were given 1, 5, or 30 inescapable preshocks in the presence of either cat odors or a hedonically neutral citronella odor and were tested 24 h later for prod burying and freezing with or without these odors. Both the cat and the citronella odors resulted in a significant reduction in burying and an increase in freezing for rats given 5 and 30 preshocks and tested in the presence of these respective conditioned odors. For the groups that were given 5 preshocks, preshock and later testing in the presence of cat odors resulted in significantly less prod burying and more freezing than for rats that were preshocked and tested in the presence of citronella. The findings of these three ethoexperimental studies are discussed in terms of the learned-helplessness theory, the stress-coping-fear-defense (SCFD) theory, and the concept of selective CS-US associability.     

Aggressive behavior in preschoolers' social networks: Do birds of a feather flock together?

In a preschool setting, the naturally occurring aggressive behavior of sixtyfour 4-year-old children was observed and recorded. Individual differences in gender, behavioral style, social competence, reciprocal friendship, and social clique membership were examined to understand how these variables might be related to children's aggressive behavior. Variations in children's aggressive behavior were found to be associated with behavior style and social competence with peers. Children within social cliques were relatively similar in the frequency of their observed aggressive behavior. The results suggest that efforts to decrease children's aggression might target groups of children rather than individuals.     

Determinants of planarian aggregation behavior

Using a filter technique, five experiments examined the role of chemical and visual cues in recruiting individual planarians to established aggregations. The results indicated thatCura foremani depend upon a combination of chemical and visual cues whilePlanaria dactyligera depend almost entirely on chemical cues for aggregation formation.     

Aggressive and nonaggressive rejected students: An analysis of their differences

The present study aimed to analyze differences between aggressive and nonaggressive rejected students in four sets of variables: personal, family, school, and social. Participants in the study were 843 Spanish adolescents ranging in age from 11 to 16 years old, of whom 47% were boys. Results indicated that these two subgroups of rejected students show a different profile. Aggressive rejected students informed of lower levels of family self‐esteem, less parental support, higher levels of aggression between their parents at home, and a more offensive parent–child communication in comparison with nonaggressive rejected adolescents. Moreover, aggressive rejected students showed lower levels of academic self‐esteem, a more negative attitude toward school and studies, poorer relationships with teachers, and more academic difficulties than did adolescents in the nonaggressive rejected subgroup. Finally, aggressive rejected students indicated the presence of more undesirable life events and changes in their lives and, in general, higher levels of perceived stress. © 2006 Wiley Periodicals, Inc. Psychol Schs 43: 387–400, 2006.     

Pavlovian appetitive discriminative conditioning inAplysia californica

Three experiments demonstrated Pavlovian appetitive discrimination learning in the marine mollusc,Aplysia californica. In each experiment, subjects were exposed to two conditioned stimuli; one stimulus (CS+) was paired with food presentations and the other stimulus (CS?) was never followed by food. In Experiments 1 and 3 different chemosensory stimuli were used, and in Experiment 2 different tactile stimuli were used. For both types of conditioned stimuli, bite responses occurred significantly more often to the CS+ than to the CS?. Experiment 2 also showed thatAplysia could learn a reversal of this discrimination. Experiment 3 showed that nonreinforced presentations of CS+ resulted in a decline in the frequency of conditioned biting. The implications of these results for neurobiological analyses of learning are discussed.     

Aggressive Boys' Hostile Perceptual and Response Biases: The Role of Attention and Impulsivity

The present study addressed whether (1) aggressive boys show hostile biases or general deficits in social perception, (2) aggressive boys' social perceptual difficulties also characterize isolate and isolate-aggressive children, (3) aggressive, isolate, and isolate-aggressive boys' social perceptual difficulties are attributable to inattention and impulsivity, and (4) aggressive and nonaggressive boys differ in the links between social perception and proposed behavioral responses. Aggressive boys demonstrated hostile biases, but not general deficits, in intention-cue detection relative to average-status boys. Isolate-aggressive boys resembled aggressive boys in social perception, whereas isolate boys showed mild deficits relative to average-status boys. Although isolates' general deficits were predominantly accounted for by inattention and impulsivity, aggressives' and isolate-aggressives' hostile biases remained after these problems were statistically controlled. The aggressive groups proposed aggressive responses much more frequently than the nonaggressive groups following intentions perceived as nonhostile. Measures corresponding to several stages of Dodge's social information processing model discriminated the aggressive from nonaggressive groups, thus providing support for this model.     

Effects of CS preexposure on inhibition of delay

Two experiments examined the effects of preexposure to a stimulus on the subsequent acquisition of conditioned suppression by rats. Variations in the level of suppression within conditioning trials were noted so thatinhibition of delay (taken here to mean less suppression at the beginning of a trial than at the end) could be detected. Inhibition of delay was observed both during the acquisition of suppression and (in Experiment 1) when suppression began to wane with continued postasymptotic training. Preexposure to the to-be-conditioned stimulus retarded acquisition of suppression and slowed the appearance of inhibition of delay both in acquisition and (in Experiment 1) in postasymptotic performance. Experiment 2 demonstrated that inhibition of delay was attenuated during conditioning that followed preexposure in which the stimulus was paired with a weak reinforcer. These results provide no support for the suggestion that preexposure to a stimulus retards later conditioning because it allows the subject to acquire information about stimulus duration that in turn fosters the development of inhibition of delay. Rather, they are compatible with the suggestion that preexposure causes the stimulus to lose associability.     

The Relation Between Toy Gun Play and Children's Aggressive Behavior

To assess the relation between toy gun play and aggression, thirty-six 3- to 5-year-olds were observed in free play in their daycare center and coded for amount of real aggression, pretend aggression, rough-and-tumble play (R & T), and nonaggressive pretend play. Based on a questionnaire completed by the parents, the children were also coded for the amount they played with toy guns in the home, the rated aggressive level of their preferred television programs, the rated aggressive level of their most preferred toys, and amount of parents' physical punishment of the children. Of all children, 56% played with toy guns in the home, most of whom were boys. Multiple regression analyses indicated that amount of parents' punishment strongly predicted real aggression in both boys and girls, and amount of toy gun play strongly predicted real aggression in boys. However, when it came to pretend aggression, aggressive level of children's preferred toys was the strongest predictor, while toy gun play negatively predicted pretend aggression. Toy gun play did not predict nonaggressive pretend play, but parents' punishment negatively predicted nonaggressive pretend play. These results indicate that toy gun play and parental punishment are positively associated with a higher level of real aggression but not pretend aggression. This pattern is discussed in terms of a cuing effect theory versus a cathartic effect theory. It also argues for distinguishing between real and pretend aggression and other forms of play in future studies.     

Modification of Reconciliation Behavior through Social Experience: An Experiment with Two Macaque Species

Reconciliation, defined as a friendly reunion between former opponents shortly after an aggressive encounter, is common in the stumptail macaque (Macaca arctoides) but rare in the rhesus macaque (M. mulatta). Juveniles of the two species were cohoused for 5 months, after which they were observed with conspecifics only. Control rhesus monkeys, matched in age and sex to the experimental subjects, went through the same procedure without exposure to the other species. A threefold increase in the proportion of reconciled fights was measured in the rhesus subjects. The difference emerged gradually during cohousing with the tutor species and was sustained following removal of this species. Other behavior, such as grooming and aggression, decreased over time. It is suggested that the social attitude of the subjects was affected through contact with a species characterized by a more relaxed dominance style.     

Social Information-Processing Mechanisms in Reactive and Proactive Aggression

Theories of aggressive behavior and ethological observations in animals and children suggest the existence of distinct forms of reactive (hostile) and proactive (instrumental) aggression. Toward the validation of this distinction, groups of reactive aggressive, proactive aggressive, and nonaggressive children were identified ( n = 624 9–12-year-olds). Social information-processing patterns were assessed in these groups by presenting hypothetical vignettes to subjects. 3 hypotheses were tested: (1) only the reactive-aggressive children would demonstrate hostile biases in their attributions of peers' intentions in provocation situations (because such biases are known to lead to reactive anger); (2) only proactive-aggressive children would evaluate aggression and its consequences in relatively positive ways (because proactive aggression is motivated by its expected external outcomes); and (3) proactive-aggressive children would select instrumental social goals rather than relational goals more often than nonaggressive children. All 3 hypotheses were at least partially supported.     

The Relation Between Toy Gun Play and Children's Aggressive Behavior

To assess the relation between toy gun play and aggression, thirty-six 3- to 5-year-olds were observed in free play in their daycare center and coded for amount of real aggression, pretend aggression, rough-and-tumble play (R & T), and nonaggressive pretend play. Based on a questionnaire completed by the parents, the children were also coded for the amount they played with toy guns in the home, the rated aggressive level of their preferred television programs, the rated aggressive level of their most preferred toys, and amount of parents' physical punishment of the children. Of all children, 56% played with toy guns in the home, most of whom were boys. Multiple regression analyses indicated that amount of parents' punishment strongly predicted real aggression in both boys and girls, and amount of toy gun play strongly predicted real aggression in boys. However, when it came to pretend aggression, aggressive level of children's preferred toys was the strongest predictor, while toy gun play negatively predicted pretend aggression. Toy gun play did not predict nonaggressive pretend play, but parents' punishment negatively predicted nonaggressive pretend play. These results indicate that toy gun play and parental punishment are positively associated with a higher level of real aggression but not pretend aggression. This pattern is discussed in terms of a cuing effect theory versus a cathartic effect theory. It also argues for distinguishing between real and pretend aggression and other forms of play in future studies.     

Hostility ratings by parents at risk for child abuse: impact of chronic and temporary schema activation

OBJECTIVE: Two studies examined whether accessibility of hostility-related schema influenced ratings of ambiguous child pictures. Based on the social information processing model of child physical abuse (CPA), it was expected that CPA risk status would serve as a proxy for chronic accessibility of hostile schema, while priming procedures were used to manipulate temporary accessibility of hostility-related schema. METHODS: Participants included 108 parents (79 low and 29 high CPA risk) in Experiment 1 and 88 parents (43 low and 45 high CPA risk) in Experiment 2. Parents were randomly assigned to either hostile or neutral priming conditions. Following the priming procedures, all parents rated pictures that depicted children who appeared ambiguous with regard to the extent to which they were being hostile/cooperative. RESULTS: In both experiments, high, compared to low, CPA risk parents rated the ambiguous child pictures as more hostile. Further, both supraliminal (Experiment 1) and subliminal (Experiment 2) exposure to hostility-related words independently increased hostility ratings. In both experiments, the influence of chronic and temporary activation of hostile schema was additive and not interactive. CONCLUSION: Findings from these experiments are consistent with the proposition that high CPA risk parents are more likely to infer hostility in response to ambiguous child cues. Further, accessibility of hostility-related schema in parents increases the likelihood of hostile inferences, which in turn may increase attributions of hostile intent and aggressive parenting behaviors.     

A Longitudinal Study of Forms and Functions of Aggressive Behavior in Early Childhood

The purpose of this study was to investigate the distinct forms (i.e., physical and relational) and functions (i.e., proactive and reactive) of aggressive behavior during early childhood ( n  =   101; M age = 45.09 months). Forms, but not functions, of aggressive behavior were stable over time. A number of contributors to aggression were associated with distinct subtypes of aggressive behavior. Females and socially dominant children were more relationally aggressive and older children were less physically aggressive than their peers. Longitudinal analyses indicated that social dominance predicted decreases in physical aggression and peer exclusion predicted increases in relational aggression. Overall, the results provide support for the distinction between subtypes of aggression in early childhood.     

Aggressive Boys in the Classroom: Biased Attributions or Shared Perceptions?

This study of 32 aggressive (AG) and 32 nonaggressive (NA) boys applied a social information processing analysis to interactions between children and their teachers. In a cue reading task, AG and NA subjects estimated teacher anger in ambiguous situations where the targets of the teacher behavior were the subjects, NA peers, and AG peers. AG boys predicted that greater teacher anger would be directed toward themselves than did NA boys. However, this could not be interpreted as an attributional bias specific to AG boys, because both NA and AG boys predicted that greater hostility would be directed toward AG boys. Target status was the primary determinant of cue interpretation. AG boys were more likely than NA boys to choose aggressive solutions to problems involving teachers and to judge aggressive solutions to be competent. The results suggested that NA subjects were actually more effective than AG subjects in enacting an aggressive response.     

Group Social Context and Children's Aggressive Behavior

Very little is known about the influence of the social-psychological context on children's aggressive behavior. The purpose of this research was to examine the interrelations of group contextual factors and the occurrence of aggressive behavior in 22 experimental play groups of 7- and 9-year-old African-American boys. Group context was examined before, during, and after an aggressive act as well as during nonaggressive periods. The results showed that there are dimensions of group context (i.e., negative affect, high aversive behavior, high activity level, low group cohesion, competitiveness) that were related to the occurrence of aggressive behavior between 2 children in the group. Group context influenced how children reacted to aggression between its members (e.g., siding with the victim), which in turn influenced the quality of the postaggression group atmosphere. This study suggests that individual-within-context information be incorporated into theories of aggression among children.