Natalie Kretsch

Pubertal Development and Peer Influence on Risky Decision Making

Adolescents engage in more risky behavior when they are with peers and show, on average, heightened susceptibility to peer influence relative to children and adults. However, individual differences in susceptibility to peer influence are not well understood. The current study examined whether the effect of peers on adolescents’ risky decision making was moderated by pubertal status. Participants (58 youth, ages 11-16, 50% male, 63.9% African American) completed a computerized measure of risky decision making, once alone and once in the presence of two peers. Pubertal status was assessed using self-report. Adolescents made riskier decisions in the presence of peers, and more advanced pubertal development predicted greater risky decision making, controlling for chronological age. The effect of peer presence on risky decision making was attenuated for adolescents with more advanced pubertal development. These findings suggest that the presence of peers may override biologically based individual differences in propensity for risk taking.

Genetic and environmental influences on testosterone in adolescents: evidence for sex differences.

The current study investigated genetic and environmental influences on salivary testosterone during adolescence, using data from 49 pairs of monozygotic twins and 68 pairs of dizygotic twins, ages 14-19 years (M = 16.0 years). Analyses tested for sex differences in genetic and environmental influences on testosterone and its relation to pubertal development. Among adolescent males, individual differences in testosterone were heritable (55%) and significantly associated with self-reported pubertal status (controlling for age) via common genetic influences. In contrast, there was minimal heritable variation in testosterone for females, and testosterone in females was not significantly associated with pubertal status after controlling for age. Rather, environmental influences shared by twins raised together accounted for nearly all of the familial similarity in female testosterone. This study adds to a small but growing body of research that investigates genetic influences on individual differences in behaviorally relevant hormones.

Beyond dual systems: A genetically-informed, latent factor model of behavioral and self-report measures related to adolescent risk-taking

The dual systems model posits that adolescent risk-taking results from an imbalance between a cognitive control system and an incentive processing system. Researchers interested in understanding the development of adolescent risk-taking use a diverse array of behavioral and self-report measures to index cognitive control and incentive processing. It is currently unclear whether different measures commonly interpreted as indicators of the same psychological construct do, in fact, tap the same underlying dimension of individual differences. In a diverse sample of 810 adolescent twins and triplets (M age = 15.9 years, SD = 1.4 years) from the Texas Twin Project, we investigated the factor structure of fifteen self-report and task-based measures relevant to adolescent risk-taking. These measures can be organized into four factors, which we labeled premeditation, fearlessness, cognitive dyscontrol, and reward seeking. Most behavioral measures contained large amounts of task-specific variance; however, most genetic variance in each measure was shared with other measures of the corresponding factor. Behavior genetic analyses further indicated that genetic influences on cognitive dyscontrol overlapped nearly perfectly with genetic influences on IQ (rA = −0.91). These findings underscore the limitations of using single laboratory tasks in isolation, and indicate that the study of adolescent risk taking will benefit from applying multimethod approaches.

Marriage, Divorce, and Alcohol Use in Young Adulthood A Longitudinal Sibling-Comparison Study

Marital status is a robust predictor of alcohol consumption in young adulthood; however, the extent to which observed associations are due to socialization or selection processes is unclear. The current study examined associations between marital status and alcohol use, assessed in a sample of 5,150 young adults (ages 18–30) from the National Longitudinal Survey of Youth. A longitudinal sibling-comparison design controlled for family-level environmental and genetic selection factors and for an individual’s premarital trajectory of alcohol use. Nested model comparisons tested whether gender and age moderated the effects of marriage and divorce. Controlling for selection factors, the transition into marriage predicted decreases in alcohol consumption, and this effect was consistent across gender and age. Divorce predicted increased consumption, particularly for men. Findings support a causal relationship between changes in marital status and alcohol use, rather than an association due to selection factors and suggest gender-specific changes in alcohol use following divorce.

Sensation seeking, peer deviance, and genetic influences on adolescent delinquency: evidence for person-environment correlation and interaction

Both sensation seeking and affiliation with deviant peer groups are risk factors for delinquency in adolescence. In this study, we use a sample of adolescent twins (n = 549), 13 to 20 years old (M age = 15.8 years), in order to test the interactive effects of peer deviance and sensation seeking on delinquency in a genetically informative design. Consistent with a socialization effect, affiliation with deviant peers was associated with higher delinquency even after controlling for selection effects using a co-twin-control comparison. At the same time, there was evidence for person-environment correlation; adolescents with genetic dispositions toward higher sensation seeking were more likely to report having deviant peer groups. Genetic influences on sensation seeking substantially overlapped with genetic influences on adolescent delinquency. Finally, the environmentally mediated effect of peer deviance on adolescent delinquency was moderated by individual differences in sensation seeking. Adolescents reporting high levels of sensation seeking were more susceptible to deviant peers, a Person × Environment interaction. These results are consistent with both selection and socialization processes in adolescent peer relationships, and they highlight the role of sensation seeking as an intermediary phenotype for genetic risk for delinquency. (PsycINFO Database Record

Academic achievement as a moderator of genetic influences on alcohol use in adolescence

Prior research suggests a link between academic performance and alcohol use during adolescence, but the degree to which this association reflects actual protective effects continues to be debated. We investigated the role of genetic factors in the association between academic achievement and adolescent alcohol use and whether achievement might constrain the translation of genetic influences on drinking into actual behavior (a Gene × Environment interaction). Analysis of twin data from Add Health (n = 399 monozygotic and dizygotic twin pairs) revealed not only common genetic factors underlying the association between achievement and alcohol consumption but also evidence for a gene-environment interaction. Specifically, the protective effect of achievement operated by moderating heritability of alcohol use, which was particularly salient for adolescents at high genetic risk for alcohol use.

Interactions between DRD4 and developmentally specific environments in alcohol-dependence symptoms.

Social experiences may moderate genetic influences on alcohol dependence (AD) symptoms. Consistent with this hypothesis, Park, Sher, Todorov, and Heath (2011) previously reported interactions between the dopamine D4 receptor gene (DRD4) and developmentally specific environments in the etiology of AD symptoms during emerging and young adulthood. Using a longitudinal cohort of n = 367 White participants followed from ages 18 to 27 years, we examine a series of similar interactions between DRD4 and developmentally sensitive contexts including childhood adversity and work and family roles. In contrast to previous results, we observed no significant interactions between DRD4 and childhood adversity. Overall, results further highlight the need for longitudinal studies of Gene × Environment interaction in the behavioral sciences and the difficulty of identifying candidate Gene × Environment interaction effects that are consistent across studies.