Genetic and Environmental Contributions to Associations between Infant Fussy Temperament and Antisocial Behavior in Childhood and Adolescence

Abstract

Previous research suggests that fussy temperament in infancy predicts risk for later antisocial behavior (ASB) in childhood and adolescence. It remains unclear, however, to what extent infant fussiness is related to later ASB through causal processes or if they both reflect the same family risk factors for ASB. The current study used two approaches, the comparison of siblings and bivariate biometric modeling, to reduce familial confounding and examine genetic and environmental influences on associations between fussiness in the first 2 years of life and ASB in childhood and late adolescence. Analyses were conducted on data from a prospective cohort (9237 at 4-9 years and 7034 at 14-17 years) who are the offspring of a nationally representative sample of US women. In the full sample, fussiness predicted both child and adolescent ASB to small but significant extents, controlling for a wide range of measured child and family-level covariates. When siblings who differed in their fussiness were compared, fussiness predicted ASB in childhood, but not ASB during adolescence. Furthermore, results from a bivariate Cholesky model suggested that even the association of fussiness with childhood ASB found when comparing siblings is attributable to familial factors. That is, although families with infants who are higher in fussiness also tend to have children and adolescents who engage in greater ASB, the hypothesis that infant fussiness has an environmentally mediated impact on the development of future ASB was not strongly supported.

Keywords: Conduct problems; Delinquency; Fussiness; Irritability; Quasiexperimental; Sibling comparison; Temperament.

Fig. 1

Path diagram for bivariate Cholesky decomposition of the covariation between fussiness and antisocial behavior outcome. Subscripts _F and _O = fussiness and outcome variable, respectively. Subscripts ₁ and ₂ indicate sibling 1 and sibling 2. A_F, C_F, and E_F = latent additive genetic, shared environmental, and nonshared environmental factors for fussiness; A_O, C_O, and E_O = latent additive genetic, shared environmental, and nonshared environmental factors for outcome variable. rA_F and rA_{O =} correlation of additive genetic factors within sibling pair for fussiness and outcome, fixed at 0.5 in full siblings and 0.25 in half siblings. rC_F and rC_{O =} correlation of shared environmental factors within sibling pair for fussiness and outcome, fixed at 1.0 in all sibling pairs. a_F, c_F, and e_F = path estimates from A, C, and E latent factors for fussiness to observed fussiness variable. a_O, c_O, and e_O = path estimates from A, C, and E latent factors for outcome variable to observed outcome variable. a_cov, c_cov, and e_cov = path estimates from A, C, and E latent factors for fussiness to observed outcome variable.