Wisconsin Twin Project Overview: Temperament and Affective Neuroscience

Childhood inhibition predicts adolescent social anxiety: Findings from a longitudinal twin study

An enduring issue in the study of mental health is identifying developmental processes that explain how childhood characteristics progress to maladaptive forms. We examine the role that behavioral inhibition (BI) has on social anxiety (SA) during adolescence in 868 families of twins assessed at ages 8, 13, and 15 years. Multimodal assessments of BI and SA were completed at each phase, with additional measures (e.g., parenting stress) for parents and twins. Analyses were conducted in several steps: first, we used a cross-lagged panel model to demonstrate bidirectional paths between BI and SA; second a biometric Cholesky decomposition showed that both genetic and environmental influences on childhood BI also affect adolescent SA; next, multilevel phenotypic models tested moderation effects between BI and SA. We tested seven potential moderators of the BI to SA prediction in individual models and included only those that emerged as significant in a final conditional model examining predictors of SA. Though several main effects emerged as significant, only parenting stress had a significant interaction with BI to predict SA, highlighting the importance of environmental moderators in models examining temperamental effects on later psychological symptoms. This comprehensive assessment continues to build the prototype for such developmental psychopathology models.

GENETIC AND ENVIRONMENTAL CONTRIBUTIONS TO POSITIVE AFFECT: INSIGHTS FROM ADOLESCENT TWINS

Disturbances in positive affect and reductions in social reward/interpersonal pleasure are common across a range of clinical disorders and are often related. We examined the relationship between the Anticipatory and Consummatory Interpersonal Pleasure Scale (ACIPS-A), and other measures of positive affect in adolescents in a genetically informative research design. The sample consisted of 177 MZ and 136 same sex DZ twins drawn from a study of adolescent twins (M = 16.4 ± .97 years) who were part of the Wisconsin Twin Project. The self-report questionnaires included the Behavioral Activation Scale (BAS), Psychological Well-Being Scale, revised Early Adolescent Temperament Questionnaire (EATQR) and the adolescent version of the ACIPS (ACIPS-A). Structural equation modeling estimated the relative contribution of genetic and environmental factors to the phenotypic variance in each of the measures. Follow-up bivariate analyses parsed the genetic and environmental contributions to the phenotypic covariances between the ACIPS-A and each of the other measures of positive affect. We found evidence of moderate heritability for the ACIPS-A scale scores. Overall, models specifying additive genetic and unique environmental effects (AE models) were the most parsimonious models for each of the measures. Several of the measures showed moderate positive phenotypic intercorrelations, and all but one of these intercorrelations showed significant partial genetic underpinnings. Moreover, the bivariate biometric analyses indicated that the ACIPS-A also captures unique heritable variation. Thus, the ACIPS-A captures unique heritable contributions to social/interpersonal pleasure, as well as shared genetic variance with other measures of positive affectivity.

Elucidating the Links Between Mother and Father Alcohol Use Disorder and Adolescent Externalizing Psychopathology: A Test of Transmission Specificity Within Competing Factor Structures and Genetic and Environmental Liabilities

Parental alcohol use disorder (AUD) is a substantiated risk factor for adolescent externalizing psychopathology; however, the level of specificity at which risk from parental AUD is transmitted to adolescent offspring should be interrogated further. The current study modeled competing factor structures of psychopathology in a sample of 502 adolescent twin pairs (Mage = 13.24 years) and tested associations with mother and father AUD. The bifactor model exhibited the best fit to the data when contrasted with correlated factors and general factor models. Paternal AUD predicted the externalizing and internalizing correlated factors, the adolescent P-factor but not the residual externalizing and internalizing factors, and the general factor. No significant associations with maternal AUD were noted. Lastly, the latent factors of adolescent psychopathology were all moderately heritable (h2 = 0.44-0.59) and influenced by the nonshared environment. Shared genetic factors primarily explained externalizing and internalizing covariance. Findings suggest that efforts to mitigate risk in offspring of fathers exhibiting AUD require broader approaches that address the full range of adolescent symptomology.