Genetic and Environmental Influences on the Association Between Pubertal Maturation and Internalizing Symptoms

The literature consistently shows an association between pubertal maturation and internalizing problems in girls. The association
for boys is less clear. The present study examines genetic and environmental influences on the association between pubertal
maturation and internalizing problems for boys and girls in two primarily Caucasian adolescent twin/sibling studies: The Swedish
Twin study of CHild and Adolescent Development (706 same-sex twin pairs aged 13–14, M = 13.7 years, 50 % female), and the
Nonshared Environment in Adolescent Development sample (US-based, 687 same-sex twin/sibling pairs aged 10–18, M = 13.6 years,
47 % female). For girls, more advanced pubertal maturation was associated modestly with more internalizing problems, and that
association was entirely explained by shared environmental influences. For boys, the association between pubertal maturation
and internalizing problems was weak and inconsistent. Results for girls were remarkably consistent across samples. Findings
suggest that nongenetic mechanisms mediate the association between pubertal maturation and internalizing problems. Findings
have implications for intervention such that environmental influences shared by twins/siblings may provide the best targets
for intervention strategies designed to minimize the potential negative effects of pubertal maturation on internalizing symptoms
in girls.