2013

Purpose: Low heart rate has been linked to antisocial behavior. However, the effect of low heart rate may be mediated by affiliation with bullies. We hypothesized that individuals with low heart rate are more likely to affiliate with bullies and in turn are influenced by these peers. Method: Data come from two waves of a subsample of the TRAILS study (N=809; 44.0% boys; mean age 11.0 at T1 and 13.5 at T2). Antisocial behavior was measured via the Antisocial Behavior Questionnaire at both waves. Heart rate was assessed during rest at T1. Affiliation with bullies was assessed via peer-nominations at T1. Possible gender differences were taken into account and all analyses were adjusted for family context (i.e., family break-up and SES). Results: Regression analyses showed that lower heart rate was only associated with antisocial behavior in (pre)adolescents who affiliated with bullies. Moreover, the effect of lower heart rate on boys’ antisocial behavior went partly via affiliation with bullies. Conclusions: Our findings show that (pre)adolescents, and in particular boys, seem to be in environments that match their biological disposition and in turn are shaped by this environment.

The moderating effects of three specific conditions (status hierarchy, attractiveness hierarchy, and sex ratio) on the link between status (popularity) and physical and relational aggression were examined in a large sample of adolescent boys (N = 1,665) and girls (N = 1,637) (M age = 13.60). In line with the hypotheses, derived from integrating a goal-framing perspective with an evolutionary perspective, it was found for boys that status was more strongly related to both physical and relational aggression in classrooms when differences in status (status hierarchy) and physical attractiveness between same-gender peers (attractiveness hierarchy) were smaller, and to relational aggression when cross-gender peers (potential mating partners) were relatively scarce. For girls, status hierarchy and attractiveness hierarchy only moderated the link between status and relational aggression. These results suggest that competition to a certain extent triggers aggression by high status adolescents. The findings are discussed from a broader evolutionary perspective, and the utility of this approach for understanding adolescents’ behavior in the peer context is considered.

 The quality of adolescents' relationships with peers can have a lasting impact on later psychosocial adjustment, mental health, and behavior. However, the effect of peer relations on later problem behavior is not uniformly strong, and genetic factors might influence this association. This study used four-wave longitudinal (11-19 years) data (n = 1,151) from the Tracking Adolescents' Individual Lives Survey, a Dutch cohort study into adolescent development to test whether the dopamine receptor D4 polymorphism moderates the impact of negative (i.e., victimization) and positive peer experiences (i.e., social well-being) on later delinquency. Contrary to our expectations, results showed that carriers of the dopamine receptor D4 gene 4-repeat homozygous variant instead of those carrying the 7-repeat allele were more susceptible to the effects of both peer victimization and social well-being on delinquency later in adolescence. Findings of our study are discussed in light of other studies into genetic moderation of peer effects on adolescent development and the possibility that developmental specifics in adolescence, such as maturation processes in brain structure and functioning, may affect the interplay of environmental and genetic factors in this period in life.

Elevated levels of corticotropin (ACTH)-reactive immunoglobulins (ACTH IgG) were found in males with conduct disorder, suggesting their involvement in the biology of antisocial behavior. We first aimed to confirm these findings in a large general population sample of adolescents. Secondly, we studied the association between ACTH IgG levels and hypothalamic-pituitary-adrenal (HPA) axis response to stress. Free and total ACTH IgG levels were measured in sera of 1230 adolescents (15-18 years). HPA axis activity was determined by measuring salivary cortisol before, during, and after a social stress test. Antisocial behavior was assessed using the Antisocial Behavior Questionnaire. ACTH peptide and IgG affinity kinetics for ACTH were assayed in a subsample of 90 adolescents selected for high or low ACTH IgG levels. In boys, higher total ACTH IgG levels were associated with higher antisocial behavior scores (β=1.05, p=0.04), especially at high levels of free ACTH IgG. In girls, antisocial behavior was associated with low free ACTH IgG levels (β=-0.20, p=0.04). Stress-induced cortisol release was associated with free ACTH IgG in boys (βareaunderthecurve=-0.67, p<0.01), and with total ACTH IgG in girls (βrecovery=0.84, p=0.05). The affinity kinetics assay showed that ACTH IgG association rates were lower in both boys and girls with high ACTH IgG levels. These data show that ACTH IgG levels are related to antisocial behavior and HPA axis response to stress in adolescents. The mechanisms behind these associations, including different ACTH binding properties of IgG in subjects with antisocial behavior, deserve further attention.

Copyright © 2013 Elsevier Ltd. All rights reserved.

In adolescence, being socially successful depends to a large extent on being popular with peers. Even though some youths have what it takes to be popular, they are not, whereas others seem to have a secret ingredient that just makes the difference. In this study the G-allele of a functional polymorphism in the promotor region of the 5HT2A serotonin receptor gene (-G1438A) was identified as a secret ingredient for popularity among peers. These findings build on and extend previous work by Burt (2008, 2009). Tackling limitations from previous research, the role of the 5HT2A serotonin receptor gene was examined in adolescent males (N = 285; average age 13) using a unique sample of the TRAILS study. Carrying the G-allele enhanced the relation between aggression and popularity, particularly for those boys who have many female friends. This seems to be an "enhancer" effect of the G-allele whereby popularity relevant characteristics are made more noticeable. There is no "popularity gene", as the G-allele by itself had no effect on popularity.

Anxiety and depressive problems have often been related to higher hypothalamic— pituitary—adrenal (HPA)-axis activity (basal morning cortisol levels and cortisol awakening response [CAR]) and externalizing problems to lower HPA-axis activity. However, associations appear weaker and more inconsistent than initially assumed. Previous studies from the Tracking Adolescents Individual Lives Study (TRAILS) suggested sex-differences in these relationships and differential associations with specific dimensions of depressive problems in a general population sample of children (10—12 years). Using the TRAILS population sample (n = 1604), we tested hypotheses on the association between single day cortisol (basal morning levels and CAR) and specifically constructed dimensions of anxiety (cognitive versus somatic), depressive (cognitive-affective versus somatic), and externalizing problems (reactive versus proactive aggression), and explored the modifying role of sex. Moreover, we repeated analyses in an independent same-aged clinic-referred sample (n = 357). Structural Equation Modeling was used to investigate the association between cortisol and higher- and lower-order (thus, broad and specific) problem dimensions based on self-reports in an integrated model. Overall, findings were consistent across the population and clinic-referred samples, as well as with the existing literature. Most support was found for higher cortisol (mainly CAR) in relation to depressive problems. However, in general, associations were weak in both samples. Therefore, the present results shed doubt on the relevance of single day cortisol measurements for problem behaviors in the milder range. Associations may be stronger in more severe or persistent psychopathology.

Although externalizing behavior problems show in general a high stability over time, the course of externalizing behavior problems may vary from individual to individual. Our main goal was to investigate the predictive role of parenting on externalizing behavior problems. In addition, we investigated the potential moderating role of gender and genetic risk (operationalized as familial loading of externalizing behavior problems (FLE), and presence or absence of the DRD4 7-repeat and 4-repeat allele, respectively). Perceived parenting (rejection, emotional warmth, and overprotection) and FLE were assessed in a population-based sample of 1768 10- to 12-year-old adolescents. Externalizing behavior problems were assessed at the same age and 212 years later by parent report (CBCL) and self-report (YSR). DNA was extracted from blood samples. Parental emotional warmth predicted lower, and parental overprotection and rejection predicted higher levels of externalizing behavior problems. Whereas none of the parenting factors interacted with gender and the DRD4 7-repeat allele, we did find interaction effects with FLE and the DRD4 4-repeat allele. That is, the predictive effect of parental rejection was only observed in adolescents from low FLE families and the predictive effect of parental overprotection was stronger in adolescents not carrying the DRD4 4-repeat allele.

The Biological Sensitivity to Context hypothesis (BSC) posits that high physiological reactivity (i.e., increases in arousal from baseline) constitutes heightened sensitivity to environmental influences, for better or worse. To test this hypothesis, we examined the interactive effects of family cohesion and heart rate reactivity to a public speaking task on aggressive/rule-breaking and prosocial behavior in a large sample of adolescents (N = 679; M age= 16.14). Multivariate analyses revealed small to medium sized main effects of lower family cohesion and lower heart rate reactivity on higher levels of aggressive/rule-breaking and lower levels of prosocial behavior. Although there was some evidence of 3-way interactions between family cohesion, heart rate reactivity, and sex in predicting these outcome variables, these interactions were not in the direction predicted by the BSC hypothesis. Instead, heightened reactivity appeared to operate as a protective factor against family adversity, rather than as a susceptibility factor. Results of the present study raise the possibility that stress reactivity may no longer operate as a mechanism of differential susceptibility in adolescence.