Adolescent twins and emotional distress: the interrelated influence of nonshared environment and social structure.

This study examined the power of nonshared environment to differentiate the development of adolescent monozygotic twins, and the extent to which this power varied across social structural contexts (e.g., ethnicity, socioeconomic status). Estimation of difference score models on 289 same-sex monozygotic twin pairs from the National Longitudinal Study of Adolescent Health revealed that differences in maternal closeness, teacher bonding, and religious participation differentiated monozygotic twins on emotional distress, with the more distressed twin typically lower on all three. Family income was the strongest structural moderator of these relations, with parental autonomy granting more important in higher income families and religious participation more important in lower income families. Finally, in some groups, one monozygotic twin's emotional distress was also associated with the other twin's familial and extrafamilial relationships. The results of this study demonstrate that interpersonal contexts can shape monozygotic twins' individual experiences within the structure of the larger society.