Prior research suggests that parenting affects children's relationships, including those with teachers, although there is variation across individuals in such effects. Given evidence suggesting that oxytocin may be particularly important for the quality of social relationships, we tested the hypotheses (a) that change in parenting from 4 to 6 years of age influences and predicts change in the student-teacher relationship from 6 to 8 years of age and (b) that this effect is moderated by a polymorphism related to the child's oxytocin receptor gene (OXTR), rs53576. In 2 studies, participants included, respectively, 652 socioeconomically diverse Norwegian children from a community sample (50.8% male; mean age of 54.9 months at first assessment) and 559 such children from 8 different U.S. locales (49.0% male; approximately 54 months at the first assessment). Norwegian results showed that change in parenting predicted change in student-teacher relationships, but only in the case of children homozygous for the A allele of rs53576 and in a manner consistent with differential-susceptibility theory: for AA carriers, when parenting changed for the worse, so did children's relationship with teachers, whereas when parenting changed for the better, the teacher-child relationships improved accordingly. Such G×E findings could not be replicated in the American sample. Results are discussed in terms of 2 contrasting models of Person-×-Environment interaction (differential susceptibility and diathesis stress) and potential reasons for failure to replicate. (PsycINFO Database Record

Children with histories of disorganized attachment exhibit diverse problems, possibly because disorganization takes at least two distinctive forms as children age: controlling-punitive and controlling-caregiving. This variation in the developmental legacy of disorganization has been attributed primarily to variations in children's rearing experiences. Here an alternative explanation of these divergent sequelae of disorganization is evaluated: one focused on genotype. Structural equation modeling was applied to data on 704 Norwegian children to test whether the catechol-O-methyltransferase Val158Met genotype moderates the effect of disorganized attachment, which was measured dimensionally at 4 years of age using the Manchester Child Attachment Story Task, on changes in aggressive behavior and social competence from ages 4 to 6. Children who scored high on disorganization and were homozygous for the valine allele displayed significantly greater increases in aggression and decreases in self-oriented social skills (e.g., self-regulation and assertiveness) over time than did their disorganized counterparts carrying the methionine allele, whereas disorganized children carrying the methionine allele increased their other-oriented social skill (e.g., cooperation and responsibility) scores more than did valine-homozygous children. These results are consistent with the controlling-punitive and controlling-caregiving behaviors observed in disorganized children, suggesting that the children's genotype contributed to variations in the social development of disorganized children.

Both genetic and environmental factors contribute to individual differences in aggression. Catechol-O-methyltransferase Val158Met (COMT), a common, functional polymorphism, has been implicated in aggression and aggression traits, as have childhood experiences of adversity. It is unknown whether these effects are additive or interactional and, in the case of interaction, whether they conform to a diathesis-stress or differential susceptibility model. We examined Gene × Environment interactions between COMT and serious life events on measures of childhood aggression and contrasted these 2 models. The sample was composed of community children (N = 704); 355 were boys, and the mean age was 54.8 months (SD = 3.0). The children were genotyped for COMT rs4680 and assessed for serious life events and by teacher-rated aggression. Regression analysis showed no main effects of COMT and serious life events on aggression. However, a significant interactive effect of childhood serious life events and COMT genotype was observed: Children who had faced many serious life events and were Val homozygotes exhibited more aggression (p = .02) than did their Met-carrying counterparts. Notably, in the absence of serious life events, Val homozygotes displayed significantly lower aggression scores than did Met carriers (p = .03). When tested, this constellation of findings conformed to the differential susceptibility hypothesis: In this case, Val homozygotes are more malleable to the effect of serious life events on aggression and not simply more vulnerable to the negative effect of having experienced many serious life events.

Internet gaming disorder (IGD) was included in the Addendum to DSM-5 as a condition for further study. Studies of community samples using a diagnostic interview are lacking, and evaluations of the proposed symptoms, comorbidities, and predictors of IGD are scarce. To provide such information participants in a Norwegian prospective community study were assessed with a clinical interview at age 10 years. Symptoms of other psychiatric disorders were measured with the Child and Adolescent Psychiatric Assessment at ages 8 and 10 (n = 740). Children, parents, and teachers provided information on demographics, temperament, intelligence, executive functions, self-concept, social skills, victimization, emotion regulation, family climate, and parenting. Results indicated that IGD was present in 1.7% (95% confidence interval, 0.7-2.7) of the participants (3.0% boys and 0.5% girls). Factor analysis revealed two factors: heavy involvement and negative consequences. The positive predictive value of withdrawal, tolerance, and unsuccessful attempts to control gaming symptoms to the disorder was low. Symptoms of other common disorders correlated weakly with IGD-symptoms (i.e., from r = 0.07 to r = 0.15). Upon adjusting for gender and gaming at age 8, only limited social and emotion regulation skills at age 8 predicted more age-10 IGD symptoms. In conclusion, IGD is already present in a small percentage of Norwegian 10-year olds. At least three of the proposed symptoms -- withdrawal, tolerance and unsuccessful attempts to control gaming -- merit further study given their weak associations with the disorder. Symptoms of IGD are only marginally associated with symptoms of other psychiatric disorders and only predicted by social skills and emotion regulation deficits.