Deindividuation and antinormative behavior: A meta-analysis.

A meta-analytic integration reviews evidence for deindividuation theory as an explanation of collective and antinormative behavior. Deindividuation theories propose a subjective deindividuated state that causes transgression of general social norms. Deindividuation research classically manipulates anonymity, self-awareness, and group size. Results of 60 independent studies showed little support for (a) the occurrence of deindividuated (antinormative) behaviors or (b) the existence of a deindividuated state. Research results were explained more adequately by situation-specific than by general social norms. Analyses indicated that groups and individuals conform more to situation-specific norms when they are "deindividuated." These findings are inconsistent with deindividuation theory but support a social identity model of deindividuation effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deindividuation, self-awareness, and disinhibition.

Assessed whether lack of self-awareness and conscious planning, group unity, and disinhibited behavior occurred together in deindividuating settings as predicted by E. Diener's (1979) theory of deindividuation. The characteristics and effects of group-induced deindividuation with non-socially-induced non-self-awareness was also compared. The 3 conditions were deindividuated, non-self-aware, and self-aware. After the manipulations, 126 undergraduates chose inhibited vs disinhibited tasks in a supposed "creativity" session, followed by a variety of deindividuation measures. Results reveal that the deindividuation group surpassed the other 2 on the deindividuation factor and on most of the individual measures. For some of the variables, the deindividuation and non-self-aware groups differed significantly, suggesting that deindividuation may not be identical in every respect to lack of self-awareness induced in a non-social way. (35 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deindividuation and anger-mediated interracial aggression: Unmasking regressive racism.

Investigated the effects of deindividuation, anger, and race-of-victim on aggression displayed by 96 White male undergraduates. Deindividuating situational cues produced an internal state of deindividuation that mediated aggressive behavior. Deindividuation theories are extended by the finding that the internal state of deindividuation was composed not only of the factors Self-Awareness and Altered Experience, but also Group Cohesiveness, Responsibility, and Time Distortion. As predicted, nonangered Whites were less aggressive toward Black than White victims, but angered Whites were more aggressive toward Blacks than Whites. Interracial behavior was consistent with new, egalitarian norms if anger was not aroused, but regressed to the old, historical pattern of racial discrimination if anger was aroused. This pattern of interracial behavior was interpreted in terms of a new form of racism: regressive racism. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of public and private self-awareness on deindividuation and aggression.

Tested the proposition, derived from the authors' (in press) differential self-awareness theory, that only 1 type of antecedent variable traditionally associated with deindividuation (attentional cues) and a single aspect of self-awareness (private) are involved in the deindividuation process. 48 male undergraduates were assigned to groups of 4 and were exposed to factorial combinations of attentional cues (internal vs external focus of attention) and accountability cues (potential accountability to authority figures and victims) and then allowed to aggress against a victim. As predicted, attentional cues affected private but not public self-awareness, whereas accountability cues altered public but not private self-attention. External attentional cues and low accountability cues disinhibited aggression relative to internal attentional cues and high accountability cues, respectively. Exposure to external attentional cues created an internal state of deindividuation, composed of reduced private self-awareness and altered experience, that mediated aggression. Two major types of collective aggression were identified: One category resulted from group members' assessments of the possibility of an authority figure's and the victim's surveillance of their attacks; the other category resulted from the decreased cognitive mediation of behavior evoked by the deindividuation process. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facilitation of social interaction through deindividuation of the target.

Hypothesized that actors want their perception of a target to be consistent with the type of interaction they expect. It was predicted that Ss expecting to aggress would deindividuate their target through the selective recall of deindividuating information. Conversely, Ss expecting a prosocial interaction should individuate the target. Further, angry Ss should deindividuate the individual who angered them. 124 male undergraduates were either angered or not angered by an experimental confederate and then given the opportunity to either shock, reward, or have no interaction with him. Ss recalled information about the confederate either prior to or after the learning task. Ss expecting to aggress deindividuated the target, whereas Ss expecting a prosocial interaction individuated him. Angry Ss deindividuated the target; nonangry Ss did not. Since the selective recall of information occurred prior to the interaction, the deindividuation (individuation) was aimed at facilitating future behavior rather than justifying it. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A test between deindividuation and emergent norm theories of crowd aggression.

In groups of 6–8, 89 female undergraduates who were either anonymous or identifiable to each other acted as an audience to a pair of discussants. Ss were given the opportunity to administer loud noise to the discussants. The response displayed to each group as an alleged average was manipulated so that Ss were led to believe that either an aggressive or a lenient norm had developed. As predicted by deindividuation theory, anonymous Ss administered significantly higher levels of noise than identifiable Ss. Anonymous Ss used equally loud noise regardless of group norm. Self-ratings provided evidence that the effects of anonymity were mediated by a psychological state of deindividuation, in addition to freedom from accountability for individual acts. There was no support for the crucial emergent norm theory prediction that aggression will be greatest when Ss who are identifiable to each other are exposed to an aggressive norm. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deindividuation and valence of cues: Effects on prosocial and antisocial behavior.

Manipulated deindividuation and valence of costume cues in a 2?×?2 factorial design. P. G. Zimbardo's (1970) theory of deindividuation suggests that deindividuation should disinhibit antisocial behavior independent of cue valence, and should reduce any influence due to cues. The theory of K. J. Gergen et al (1973) suggests that cues may have increasing influence, given deindividuation, and that deindividuation may increase prosocial behavior, given positive cues, and increase antisocial behavior, given negative cues. Results support Gergen's position. Given options to increase or decrease shock level received by a stranger, no main effect was found for deindividuation. There was a main effect for costume cues, and an interaction of cues with deindividuation, with deindividuation facilitating a significant increase in prosocial responses in the presence of positive cues and a nonsignificant increase in antisocial responses in the presence of negative cues. Also cues interacted with trial blocks, prosocial behavior increasing with positive cues and antisocial behavior increasing with negative cues over trial blocks. (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deindividuation: Effects of group size, density, number of observers, and group member similarity on self-consciousness and disinhibited behavior.

Predictions about the social causes of self-consciousness in groups were derived from the theory of deindividuation and tested in 3 experiments with 618 university students and adults. In Exp I, it was found that increasing group size was related to a decrease in self-consciousness. Group density did not influence self-consciousness. In Exp II, it was found that increases in the number of observers increased self-consciousness. In Exps I and II, self-reports of self-consciousness were independent of one's group, whereas the degree of behavioral disinhibition was highly correlated within groups. In Exp III, it was found that gender similarity within a group was related to lower self-consciousness. Findings support a perceptual/attentional model of self-consciousness within groups. Contrary to deindividuation theory predictions, however, behavior intensity did not vary across conditions in Exps I and II, even though self-consciousness did differ. This finding suggests that deindividuation theory is incomplete in its present form. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Alternative approaches to deindividuation.

Reviews two approaches to deindividuation research and theory. One approach has been to view deindividuation as a loss of restraints, afforded by anonymity and other forms of depersonalization. Theorists adopting this perspective, which has its origins in crowd theory, view the experience of deindividuation as a positively affective event. Theorists adopting the other view predict that deindividuation arouses negative affect and serves as a stimulus for behavior that establishes the uniqueness and continuity of a person's self-conceptions. Research testing each approach is reviewed, and areas for possible integration are posited. (104 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vicarious reinforcement and imitative learning.

The present experiment was designed to study the influence of response-consequences to the model on the imitative learning of aggression. Nursery school children were assigned randomly to 1 of the following groups: aggressive model-rewarded; aggressive model-punished; a control group shown highly expressive but nonaggressive models; and a 2nd control group which had no exposure to models. The children were then tested for the incidence of postexposure imitative and nonimitative aggressive responses. Children who witnessed the aggressive model rewarded showed more imitative aggression and preferred to emulate the successful aggressor than children in the aggressive model-punished group who both failed to reproduce his behavior and rejected him as a model for emulation. Control over aggression was vicariously transmitted to boys by the administration of aversive stimuli to the model, and to girls by the presentation of incompatible prosocial examples of behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Marital and severe parent-to-adolescent physical aggression in clinic-referred families: Mother and adolescent reports on co-occurence and links to child behavior problems.

This study examined the interplay of marital and severe parental physical aggression, and their links to child behavior problems, in 232 families of clinic-referred adolescents. Combined reports from mothers and adolescents indicated that two thirds of adolescents exposed to marital aggression in the past year had also experienced parental aggression. Mothers and fathers who used and/or were victims of marital aggression were both more likely to direct aggression toward their adolescent. Mother and youth reports of marital aggression were tied to each party's report of greater externalizing problems and to youth reports of greater internalizing problems. Severe parental aggression uniquely predicted maternal reports of both behavior problems, after controlling for marital aggression; the reverse was not true. Also, adolescents exposed to both types of family aggression did not display greater maladjustment than those subjected to only one type of family aggression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relation between types of aggression and sociometric status: Peer and teacher perceptions.

Examined the relation between aggressive behavior and sociometric status (the extent to which a child is liked by his or her peers) in third and fourth graders. 47 boys and 51 girls from a northern New England elementary school were given a group-administered peer rating of social status and a peer nomination measure assessing five types of aggressive behavior. Teachers of the same children were given modified versions of these measures. Significant negative correlations were found between social status and all categories of aggressive behavior for both sexes except provoked physical aggression in boys for which the correlation was not significant. Indirect aggression (tattling, stealing, or breaking others' property) was the type of aggressive behavior that correlated most highly with low peer ratings. There were significant differences between boys and girls on all five categories of aggressive behavior. Teachers' ratings of peer social status correlated more highly with boys' ratings than with girls' ratings, and teacher perceptions of aggressive behavior correlated significantly and positively with peers' ratings on only two categories, unprovoked physical aggression and indirect aggression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The aggression paradox: Understanding links among aggression, sensation seeking, and the consideration of future consequences.

Four studies involving 573 female and 272 male college students demonstrated that multiple forms and measures of aggression were associated with high levels of sensation seeking, impulsivity, and a focus on the immediate consequences of behavior. Multiple regression analyses and structural equation models supported a theoretical model based on the general aggression model (C. A. Anderson & B. J. Bushman, 2002), positing that hostile cognition and negative affect mediate the relationships between the aforementioned individual differences and aggression. Sensation seeking also predicted a desire to engage in physical and verbal aggression. The final study demonstrated that relative to those scoring low, individuals scoring high on the consideration of future consequences are only less aggressive when aggression is likely to carry future costs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Enhanced maternal aggression and associated changes in neuropeptide gene expression in multiparous rats.

Although it has often been speculated that prior reproductive experience improves subsequent maternal care, few studies have examined specific changes in behavior during a 1st versus 2nd lactation. During lactation, mothers display heightened aggression toward male intruders, purportedly to protect vulnerable young. In the current study, maternal aggression was examined in primiparous and age-matched multiparous females on postpartum days 5 (PPD5) and PPD15. Expression of oxytocin, oxytocin receptor, arginine vasopressin, arginine vasopressin V1a receptors, and corticotrophin-releasing hormone mRNA was measured following aggression testing at both time points using real-time quantitative PCR in brain regions previously implicated in the regulation of maternal aggression. Multiparity significantly enhanced maternal aggression on PPD5 but not on PPD15. In addition, this increased aggression was associated with region- and gene-specific changes in mRNA expression. These findings indicate that reproductive experience enhances maternal aggression, an effect that may be mediated by region-specific alterations in neuropeptidergic activity. The adaptations observed in multiparous females provide an innate model for the study of neuroplasticity in the regulation of aggression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relational aggression, gender, and peer acceptance: Invariance across culture, stability over time, and concordance among informants.

It has been proposed that overt physical and verbal aggression are more prevalent among boys and that covert aggression in the context of interpersonal relationships is more typical of girls. The purpose of this study was to replicate and extend American research on this topic to Italy. Italian elementary school pupils (n?=?314) and their teachers provided nominations for aggression and prosocial behavior on 2 occasions within a single school year. Both peer and teacher nominations were highly stable, though there was very poor concordance between them. Peer nominations for both overt and relational aggression were linked to peer rejection. Contrary to expectations, boys scored higher than girls in both overt and relational aggression. Nevertheless, on the basis of the gender composition of extreme groups, the authors conclude that the distinction between overt and relational aggression is as useful in facilitating research on aggressiveness among girls in Italy as it is in the United States. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Internet identifiability and beyond: A model of the effects of identifiability on communicative behavior.

K. Douglas and C. McGarty (2001) demonstrated that being identifiable to an in-group audience in a computer-mediated communication (CMC) setting leads people to describe anonymous out-group targets in more abstract or stereotypical ways. On the basis of these findings and the social identity model of deindividuation effects (SIDE; S. Reicher, R. Spears, & T. Postmes, 1995), the authors aimed to test a model of the effects of identifiability on communicative behavior in and beyond CMC. Participants in 3 studies, 1 CMC and 2 pen and paper, were asked to write responses to controversial messages. In all 3 studies, communicators who were identifiable to an in-group audience used more stereotypical language to describe anonymous out-group targets. Studies 2 and 3 suggested that rather than being strategic, this may result from more subtle or implicit communicative processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Peer experiences and social self-perceptions: A sequential model.

This study evaluated a social process model describing how aggression and withdrawal lead to negative social self-perceptions. The model posited both direct (i.e., cognitions associated with withdrawal) and indirect (i.e., mediations of negative peer status and peer experiences) influences. Eight- to 10-year-old children (n?=?793) completed peer assessment measures of aggression, withdrawal, peer status, victimization and affiliations, and self-reports of loneliness, perceived acceptance, and perceived behavior–conduct. As expected, the model was supported for social self-perceptions but not for perceived behavior–conduct. Withdrawn behavior uniquely predicted social self-perceptions. Both negative peer status and peer victimization successively mediated the impact of social behavior on loneliness and perceived acceptance. Classroom affiliations did not mediate social self-perceptions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stress-induced asymmetric frontal brain activity and aggression risk.

Impersonal stressors, not only interpersonal provocation, can instigate aggression through an associative network linking negative emotions to behavioral activation (L. Berkowitz, 1990). Research has not examined the brain mechanisms that are engaged by different types of stress and serve to promote hostility and aggression. The present study examined whether stress exposure elicits more left than right frontal brain activity implicated in behavioral approach motivation and whether this lateralized brain activity predicts stress-induced aggression and hostile/aggressive tendencies. Results showed that (a) participants in the impersonal (assigned to stress by a computer) and interpersonal (assigned to stress by a provoking confederate) stress conditions both showed more left than right frontal electroencephalogram activity after condition assignment and stress exposure and (b) the 2 stress groups exhibited subsequent increases in aggression relative to the no-stress group. Importantly, left frontal asymmetry in response to stress exposure predicted increases in subsequent aggressive behavior, a finding that did not emerge in the no-stress condition. Thus, both the interpersonal and impersonal stressors impacted state changes in brain activity related to behavioral approach, suggesting that stress reactivity involving approach activation represents risk for behavioral dysregulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Moderators and mediators of the stress-aggression relationship: Executive function and state anger.

The present study examined the effects of executive function (i.e., EF) and anger/hostility on the relationship between stress (across individual stress domains, as well as at the aggregate level) and aggression. Two independent groups of participants—a college sample and a low-income community sample—were administered a battery of self-report measures concerning the subjective experience of stress, aggressive behaviors, and feelings of state anger and hostility in the last month, along with a battery of well-validated neuropsychological tests of EF. Across both samples, the stress domains that demonstrated the strongest associations with aggression were those involving chronic strains of daily living (e.g., job, financial, health) versus interpersonal stressors (e.g., family, romantic). In the community sample, analyses also revealed a significant interaction between perceived stress (aggregated across domains) and EF in predicting aggressive behavior. Specifically, participants with relatively low EF abilities, across different EF processes, showed a stronger relationship between different domains of stress and aggression in the last month. Similar effects were demonstrated in the college sample, although the interaction was not significant. In both samples, experiences of anger and hostility in the last month mediated the relationship between perceived stress (aggregate) and aggressive behavior among those low, but not high, in EF. These findings highlight the importance of higher-order cognitive processes in regulating appropriate affective and behavioral responses across different types of individuals, particularly among those experiencing high levels of stress. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Intellectual functioning and aggression.

In a 22-year study, data were collected on aggressiveness and intellectual functioning in more than 600 subjects, their parents, and their children. Both aggression and intellectual functioning are reasonably stable in a subject's lifetime and perpetuate themselves across generations and within marriage pairs. Aggression in childhood was shown to interfere with the development of intellectual functioning and to be predictive of poorer intellectual achievement as an adult. Early IQ was related to early subject aggression but did not predict changes in aggression after age 8. Differences between early IQ and intellectual achievement in middle adulthood were predictable from early aggressive behavior. A dual-process model was offered to explain the relation between intellectual functioning and aggressive behavior. We hypothesized that low intelligence makes the learning of aggressive responses more likely at an early age, and this aggressive behavior makes continued intellectual development more difficult. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)