Gender Differences in Psychopathic Traits,Types, and Correlates of Aggression Among Adjudicated Youth

The current study investigated gender differences in types and correlates of aggression among 150 adjudicated youth (M age = 15.2, SD = 1.4). In cluster analysis, consistent with past studies, one aggressive group characterized by moderate levels of reactive aggression and one characterized by high levels of proactive and reactive aggression emerged and these patterns were consistent across gender. For both boys and girls, the combined proactive/reactive aggression cluster showed the greatest levels of aggression, impulsivity, and callous-unemotional traits, supporting a severity over a typology model of proactive and reactive aggression. Girls displayed significantly higher rates of physical and relational aggression than boys. Girls were highly aggressive toward both girls and boys, whereas boys were highly aggressive only toward other boys. Girls also showed multiple indications of severity and emotionality, indexed by higher rates of negative affect, anxiety, distress about social provocations, and empathy.     

Hypothalamic Pituitary Adrenal Axis Functioning in Reactive and Proactive Aggression in Children

The purpose of this study was to examine the association between hypothalamic-pituitary-adrenal axis (HPA-axis) reactivity and proactive and reactive aggression in pre-pubertal children. After a 30-min controlled base line period, 73 7-year-old children (40 males and 33 females) were randomly assigned to one of two experimental tasks designed to elicit fear (N = 33) or frustration (N = 32), or a validity check condition (N = 8). This was followed by a 60-min controlled regulation phase. A total of 17 saliva samples for cortisol analysis were collected including 12 post-stress samples at 5-min intervals. Reactive and proactive aggression levels were assessed via the teacher-completed Aggression Behavior Teacher Checklist (Dodge and Coie, J Pers Soc Psychol, 53(6), 1146–1158, 1987). Reactive aggression significantly predicted total and peak post-stress cortisol regardless of stress modality. Proactive aggression was not a predictor of any cortisol index. Examination of pure reactive, proactive, combined, or non-aggressive children indicated that reactive aggressive children had higher cortisol reactivity than proactive and non-aggressive children. Our data suggest that while an overactive HPA-axis response to stress is associated with reactive aggression, stress induced HPA-axis variability does not seem to be related to proactive aggression.     

The Development of Aggression During Adolescence: Sex Differences in Trajectories of Physical and Social Aggression Among Youth in Rural Areas

To describe trajectories of aggressive behaviors for adolescents living in rural areas, we compared the patterns, timing and sex differences in development of physical and social aggression using five waves of data collected from youth in school surveys administered over 2.5 years. The sample (N = 5,151) was 50.0% female, 52.1% Caucasian and 38.2% African-American. Multilevel growth curve models showed that physical and social aggression followed curvilinear trajectories from ages 11 to 18, with increases in each type of aggression followed by subsequent declines. Physical aggression peaked around age 15; social aggression peaked around age 14. Boys consistently perpetrated more physical aggression than girls, but the trajectories were parallel. There were no sex differences in the perpetration of social aggression. Given the characteristics of the developmental trajectories observed, interventions with both boys and girls targeting physically and socially aggressive behaviors are needed in early adolescence to slow the development of aggression.     

Predictors and Outcomes Associated with Trajectories of Revenge Goals from Fourth Grade through Seventh Grade

The present study identified longitudinal trajectories of revenge goals in a sample of at-risk youth (N = 240; 63.3% male) followed from fourth grade through seventh grade. Three revenge goal trajectory groups were identified: a low-stable group, an increasing group, and a decreasing group. The increasing and decreasing groups were initially more behaviorally and affectively dysregulated and believed that aggression would gain them more rewards relative to the low-stable group. The increasing group was also more fearfully reactive compared to the decreasing group. Revenge goal trajectory groups also predicted trajectories of reactive and proactive aggression from 4th through 7th grade. The increasing group was more reactively aggressive and depressed and had poorer social skills in 8th grade compared to the other groups. Together, results highlight the importance of considering revenge motivations as an indicator of risk and a potential focus for intervention.     

Peer Victimization and Aggression: Moderation by Individual Differences in Salivary Cortiol and Alpha-Amylase

This research examined whether variations in salivary measures of the hypothalamic-pituitary-adrenal axis (cortisol) and autonomic nervous system (alpha amylase [sAA]) contribute to individual differences in the association between peer victimization and aggression. Children (N = 132; M age = 9.46 years, SD = 0.33) completed a measure of peer victimization, teachers rated children’s aggression, and children’s saliva was collected prior to, and following, participation in a laboratory-based peer-oriented social challenge task. Children rated their level of frustration at the end of the task. Results revealed that victimization interacted with cortisol and sAA measured in anticipation of the task to predict aggression; the victimization × cortisol contribution to aggression was partly mediated by children’s self-reported frustration level. Victimization also was associated with heightened frustration in girls with high task-related sAA reactivity. Task-related sAA reactivity was associated with heightened aggression, but only for girls. These findings suggest that associations between peer victimization and aggression are moderated by variation in the activity of the major components of the psychobiology of stress; results are discussed in relation to theoretical models of individual differences in biological sensitivity to context.     

Longitudinal Investigation of the Link Between Proactive and Reactive Aggression and Disciplinary Actions in an After-School Care Program

The current study longitudinally investigated relations between proactive (goal-oriented, calculated) and reactive (response to perceived threat) aggression and disciplinary actions in an after-school care program in a sample of 147 school-age children (Mean age = 8.22 years; 54.4% male). In addition, perceived best friend delinquency was examined as a moderator of the relations between proactive and reactive aggression and disciplinary actions. As expected, high levels of proactive aggression were associated with high levels of disciplinary actions. Reactive aggression, in contrast, was negatively associated with disciplinary actions 2-months later. Finally, perceived best friend delinquency moderated the association between proactive, but not reactive, aggression and disciplinary actions. However, this interaction effect was only marginally statistically significant (p = .06). Implications for findings and future directions are discussed.     

Coping with Social Stress: Implications for Psychopathology in Young Adolescent Girls

This study investigated the impact of social stress on symptoms of psychopathology at the entry into adolescence (111 girls, Mage = 11.84, SD = 0.77). We examined whether peer stress and pubertal timing were associated with internalizing distress and aggression, and whether responses to stress and cortisol reactivity mediated or moderated these associations. Cortisol samples were collected from saliva samples during in-home visits, and the YSR was used to assess psychopathology. Interestingly, pubertal timing demonstrated a trend association with cortisol. Responses to stress mediated the association between social stress and symptoms of internalizing distress and aggression. Specifically, early maturers and girls with higher levels of peer stress exhibited more problematic responses to stress, in turn demonstrating higher levels of internalizing distress and aggression. Significant moderation effects also emerged. For example, early maturers who experienced higher levels of emotional/cognitive numbing in response to peer stress were at greater risk for aggression. Findings identify coping strategies that may be used in evidence-based programming to help girls transition more successfully into adolescence will be discussed.

Relational Aggression and Hostile Attribution Biases: Testing Multiple Statistical Methods and Models

The present study used both categorical and dimensional approaches to test the association between relational and physical aggression and hostile intent attributions for both relational and instrumental provocation situations using the National Institute of Child Health and Human Development longitudinal Study of Early Child Care and Youth Development (M = 8.3 years-old, SD = 0.19, N = 840). A one standard deviation threshold was used to create categorical aggression status groups. In categorical analyses, children who were both relationally and physically aggressive were found to attribute more hostile intent attributions in relationally provocative situations. Results from the dimensional analyses indicated that female gender, physical aggression, and hostile attribution biases for instrumental provocations each predicted increases in relational aggression over time. Further, relational aggression was not predictive of hostile attribution biases for relational provocations, and instead physical aggression was predictive. Implications for the fields of developmental psychology and psychopathology are discussed.     

Proactive and Reactive Aggression and Physical Activity

The current study examined relations between physical activity and proactive and reactive aggression. Additionally, physical activity was examined as a potential moderator of the associations between these subtypes of aggression and peer delinquency. Relations were examined in a community recruited sample of 89 children (56% male, 74% Caucasian) ranging from 9 to 12 years of age (M = 10.44, SD = 1.14). As expected, physical activity was negatively related to proactive aggression and unrelated to reactive aggression. Moreover, physical activity moderated the relation between proactive aggression and peer delinquency, such that at high levels of physical activity, proactive aggression was unrelated to peer delinquency but at low levels of physical activity, proactive aggression was positively associated with peer delinquency. Thus, physical activity may be an important factor to consider when understanding the link between aggression and other problem behavior, as physical activity appears to impact the link between proactive aggression and delinquent peer affiliations.     

Aggression Among Children with ADHD,Anxiety, or Co-occurring Symptoms: Competing Exacerbation and Attenuation Hypotheses

Competing hypotheses for explaining the role of anxiety in the relation between attention-deficit/hyperactivity disorder (ADHD) symptoms and childhood aggression were evaluated. Two studies tested whether anxiety exacerbated, attenuated, or had no effect on the relation between ADHD and aggression subtypes among psychiatrically hospitalized children. In Study 1 (N = 99), children who scored above clinical cut-off levels for anxiety only, ADHD only, and co-occurring ADHD and anxiety were compared on aggression subtypes (i.e., reactive, proactive, overt, and relational aggression). In Study 2, the moderating role of anxiety on the relation between ADHD and aggression subtypes was examined with a larger sample (N = 265) and with continuous variables. No support was found for either the attenuation or exacerbation hypothesis, and results remained consistent when separately examining hyperactivity/impulsivity and inattention symptoms of ADHD. Although ADHD symptoms were significantly associated with all aggression subtypes, this association did not remain when including symptoms of oppositional defiant disorder.     

Types of Aggression,Responsiveness to Provocation,and Callous-unemotional Traits in Detained Adolescents

The present study investigated differences in the behavioral and psychophysiological responses to provocation and in the level of callous-unemotional traits in boys exhibiting different patterns of aggression. Eighty-five boys (ages 13-18) in a juvenile detention center played a competitive computer task against a hypothetical peer who provided low and high levels of provocation. Youth high on both self-reported reactive and proactive aggression showed different behavioral responses to provocation than youth high on only reactive aggression. Specifically, the combined group showed high levels of aggressive responses without any provocation, whereas the group high on reactive aggression showed an increase in aggressive responding to low provocation. Further, results revealed a trend for the combined group to show lower levels of skin conductance reactivity to low provocation if they were also high on callous-unemotional traits.     

Do They Get What They Want or Are They Stuck With What They Can Get? Testing Homophily Against Default Selection for Friendships of Highly Aggressive Boys. The TRAILS Study

In this study a homophily selection hypothesis was tested against a default selection hypothesis, to answer whether preferred and realized friendships of highly aggressive boys differed. In a large peer-nomination sample, we assessed who highly overt aggressive, low prosocial boys (n = 181) nominated as friends (preferred friendships) and who among the nominated friends reciprocated the friendship (realized friendships). These preferred and realized friendships were compared with those of less aggressive (n = 1,268) and highly aggressive but also prosocial boys (bi-strategics; n = 55). Results showed that less aggressive boys preferred peers low on aggression, whereas highly aggressive and bi-strategic boys preferred peers not particular high or low on aggression. In line with default selection, highly aggressive boys ended up with aggressive peers even though that was not their preference. In general, received support proved an important determinant of highly aggressive, bi-strategic, and less aggressive boys’ preferred and realized friendships. Especially highly aggressive boys preferred emotionally supportive friends, but ended up with the least supportive peers. In sum, for friendships of highly overt aggressive boys, the evidence favors default selection over homophily selection.     

Differential Associations Between Relational and Overt Aggression and Children’s Psychosocial Adjustment

Although much research has focused on the association between childhood aggression and negative psychosocial adjustment, the link between the subtypes of aggression and adjustment is less clear, particularly for relational aggression. The current study examined whether overt and relational aggression in childhood (M = 10.4 years, SD = 1.1) are differentially associated with four psychosocial adjustment outcomes (i.e., academic performance, social problems, depression, and delinquency). Results indicated that relational aggression was negatively associated with academic performance, while overt aggression was positively associated with delinquency. Additionally, findings suggested gender differences in the link between aggression subtypes and social problems. Specifically, overt aggression was positively associated with social problems for boys and relational aggression was positively associated with social problems for girls. Neither subtype of aggression was uniquely associated with depression. Thus, this study suggests that psychosocial outcomes may differ depending on the form of aggression that is utilized.     

Self-Reported Psychopathic Traits in Children: Their Stability and Concurrent and Prospective Association with Conduct Problems and Aggression

The current study investigated the 18-month stability of self-reported psychopathic traits measured through the Youth Psychopathic traits Inventory–Child Version (YPI-CV) and their concurrent and prospective associations with conduct problems and aggression in a sample of 9–12 year olds (n = 159, 52% boys) from the community. Self-reported psychopathy scores were moderately to highly stable and traits were positively related to conduct problems both concurrently and at follow-up, the latter even after controlling for initial levels of conduct problems. Higher self-reported psychopathic traits were also related to higher reactive, but particularly proactive aggression at follow-up. Finally, children with persistently high levels of psychopathic traits exhibited higher levels of conduct problems and proactive aggression at follow-up than those with unstable or stable low psychopathic traits.     

Executive Functions in Preschool Children with Aggressive Behavior: Impairments in Inhibitory Control

The question whether executive function (EF) deficits in children are associated with conduct problems remains controversial. Although the origins of aggressive behavior are to be found in early childhood, findings from EF studies in preschool children with aggressive behavior are inconsistent. The current study aimed to investigate whether preschool children with aggressive behavior show impairments in EF. From a population-based sample, 82 preschool children who were showing aggressive behavior as indicated by scores at or above the 93rd percentile on the Aggressive Behavior Scale of the CBCL 1 1/2-5 were selected. These children with aggressive behavior were matched on IQ to a group of typically developing control children (N = 99). Six neuropsychological tasks were administered to assess set shifting, inhibition, working memory and verbal fluency. A factor analysis was conducted which yielded one clear factor: inhibition. Aggressive preschool children showed poorer performance on this inhibition factor than control children and boys performed worse on this factor than girls. This association between aggressive behavior and inhibition deficits was maintained after controlling for attention problems. In addition, gender differences in all EFs measured were found with boys exhibiting more impairment in EF than girls. These findings demonstrate that preschool children with aggressive behavior show impairments in inhibition, irrespective of attention problems.     

The Latent Structure of Youth Responses to Peer Provocation

This study examined whether the three categories often applied to children’s behavior—aggressive, avoidant, and assertive—actually capture the structure of a naturalistic sample of youth behavior coded at a more micro level. A sample of lower-income youth (N = 392; M age = 12.69, SD = 0.95) completed a new multiple-choice measure asking them to select responses to scenarios depicting physical, verbal, and relational provocation by a peer. Youth responses to the vignettes showed the expected associations with self-reported aggression and regulation of anger, providing preliminary evidence for the convergent validity of the measure. Factor analysis confirmed that responses loaded on three factors: aggression, avoidance, and assertion. Model fit was adequate (RMSEA = .028) and cross-validated in a second sample (RMSEA = .039). Several types of responses loaded on two factors suggesting that some strategies that youth use to manage provocation are not “pure” examples of these broadband categories. Implications for conceptualization and measurement of youth social behavior are discussed.     

Social preference,social prominence,and group membership in late elementary school: homophilic concentration and peer affiliation configurations

This study investigated the social preference and social prominence of 622 5th graders (290 boys, 332 girls) in relation to peer group membership. The sample was recruited from 11 elementary schools in a southeastern state. The ethnicity of participants was 55% European American, 41% African American, and 4% other. Peer groups were classified on each of three domains (academic, aggression, popular) by the proportion of group members who were high on the characteristic of interest. Participants’ peer affiliations were also classified with cluster analytic techniques that yielded distinct configurations of aggression, popularity, and academic competence. Social preference and social prominence were each related to popular peer group type for both boys and girls and differentially related to aggressive and academic group types. Social prominence, but not social preference, was related to peer group configurations for both girls and boys. Implications for the development of social contextual interventions to support students’ adjustment and academic engagement during late elementary school are discussed.     

Friendship as Protection from Peer Victimization for Girls with and without ADHD

The goal of this study was to examine the ability of friendship to moderate the association between behavioral risk and peer victimization for girls with attention-deficit/hyperactivity disorder (ADHD; n = 140) and comparison girls (n = 88) in a 5-week naturalistic summer camp setting. Participants were an ethnically and socioeconomically diverse group of girls ages 6–12. Parents and teachers reported on pre-summer internalizing behavior, externalizing behavior, and social competence. Participants reported on friendships and peer victimization through a peer report measure at the summer camps; friendship was scored via mutual nominations. Pre-summer externalizing behavior, internalizing behavior, and low social competence predicted peer victimization at the summer camps. Friendship moderated the association between behavioral risk and victimization for the entire sample, such that the presence of at least one friend reduced the risk of victimization. Additional analyses suggested that girls with ADHD were no more or less protected by the presence of a friendship than were comparison girls. Finally, preliminary analyses suggested that girls having only friends with ADHD were not significantly less protected than girls with at least one comparison friend. Future directions and implications for intervention are discussed.     

Differential Genetic and Environmental Influences on Reactive and Proactive Aggression in Children

While significant heritability for childhood aggression has been claimed, it is not known whether there are differential genetic and environmental contributions to proactive and reactive forms of aggression in children. This study quantifies genetic and environmental contributions to these two forms of aggression in an ethnically diverse urban sample of 9–10 year old twins (N = 1219), and compares results across different informants (child self-report, mother, and teacher ratings) using the Reactive–Proactive Aggression Questionnaire (RPQ). Confirmatory factor analysis of RPQ items indicated a significant and strong fit for a two-factor proactive–reactive model which was significantly superior to a one-factor model and which replicated across gender as well as the three informant sources. Males scored significantly higher than females on both self-report reactive and proactive aggression, findings that replicated on mother and teacher versions of the RPQ. Asian–Americans scored lower than most ethnic groups on reactive aggression yet were equivalent to Caucasians on proactive aggression. African–Americans scored higher than other ethnic groups on all measures of aggression except caregiver reports. Heritable influences were found for both forms of aggression across informants, but while boys’ self-reports revealed genetic influences on proactive (50%) and reactive (38%) aggression, shared and non-shared environmental influences almost entirely accounted for girls’ self-report reactive and proactive aggression. Although genetic correlations between reactive and proactive aggression were significant across informants, there was evidence that the genetic correlation was less than unity in boys self reported aggression, indicating that genetic factors differ for proactive and reactive aggression. These findings provide the first evidence for varying genetic and environmental etiologies for reactive and proactive aggression across gender, and provide additional support for distinction between these two forms of aggression.     

New Directions in Measuring Reactive and Proactive Aggression: Validation of a Teacher Questionnaire

The well-known distinction between reactive and proactive aggression is theoretically important but empirically controversial. Recently, aggression researchers have argued that we should separate the form and function of aggression to make a clearer distinction between reactive and proactive aggression. This article describes the validation of a new teacher-report Instrument for Reactive and Proactive Aggression (IRPA) that assesses the form separate from the function of aggression. We demonstrated good discriminant, convergent, and construct validity of the IRPA in a sample of 427 children aged 10 to 13. Reactive and proactive functions of aggression were independent constructs (r = 0.03) which indicates excellent discriminant validity. Convergent validity was satisfactory; scores from the IRPA were moderately to highly related to scores from the widely used Teacher Rating Instrument, TRI (Dodge and Coie in Journal of Personality and Social Psychology 53:1146–1158, 1987). Additionally, reactive and proactive aggression showed unique correlations with most a priori hypothesized theoretically relevant variables, which indicates construct validity. (150 words)