Serotonergic sensitivity alleles moderate relations between attachment security at age three and socioemotional competence at age five

Genetic Contributions on Attachment in Emerging Adults: Cumulative Effects of Serotonergic Polymorphisms

Attachment in emerging adults is closely intertwined with emotion regulation, stress coping, and social bonding during the transition from childhood to early adulthood. Due to the critical roles of serotonin in these mental functions, this research explored whether the cumulative genetic effects of serotonergic polymorphisms are associated with individual differences and contextual variations in attachment dimensions over time in emerging adults. Study 1 utilized a cross-sectional design in college students (N = 1088, mean age = 22.71 ± 2.86 years). The results showed significant correlations between a higher cumulative genetic score and elevated levels of attachment anxiety and avoidance. Study 2 employed a three-wave longitudinal design in a cohort of freshmen (N = 523, mean age = 19.54 ± 1.86 years at wave 1). The results demonstrated that a higher genetic score was associated with both higher levels and greater variability in attachment dimensions compared to a lower genetic score. These findings suggest that the cumulative genetic effects of serotonergic polymorphisms contribute to individual differences and dynamic processes in attachment dimensions in emerging adults.

Longitudinal Influences of DRD4 Polymorphism and Early Maternal Caregiving on Personality Development and Problem Behavior in Middle Childhood and Adolescence

Most studies examining gene-environment effects on self-regulation focus on outcomes early childhood or adulthood. However, only a few studies investigate longitudinal effects during middle childhood and adolescence and compare two domains of early caregiving. In a longitudinal follow-up with a sample of N = 87, we studied the effects of differences in the DRD4 tandem repeat polymorphisms and two domains of early maternal caregiving quality on children’s personality development using Block’s California Child Q-Set (CCQ) at age six and age 12 and on problem behavior at ages six and seven. Early maternal regulation quality predicted later ego-resiliency and aggressiveness. In addition, significant gene-environment interactions revealed that children with the 7+ DRD4 tandem repeat polymorphism and poor maternal regulation quality in infancy showed lower scores in ego-resiliency and higher scores in ego-undercontrol and CCQ aggressiveness. In contrast, children who had experienced effective maternal regulation in infancy showed a comparable level in personality traits and problem behavior as the DRD4 7- group independent of the levels of maternal regulatory behavior. Similarly, longitudinal caregiving × DRD4 interactions were found for behavior problems in middle childhood, especially for oppositional-aggression, inattentive-hyperactivity, and social competence. Early caregiving effects were only found for maternal regulation quality, but not for maternal responsiveness. Effective early maternal regulation in infancy can moderate the negative effect of DRD4 7+ on children’s self-regulation in middle childhood and adolescence. However, maternal responsiveness has no comparable effects. It seems relevant to consider several dimensions of early caregiving and to also measure the environment in more detail in gene-environment studies.