The genetic and environmental contributions to oppositional defiant behavior: a multi-informant twin study.

OBJECTIVE To estimate the genetic and environmental contributions to oppositional defiant behavior (ODB) from mother, father, and teacher report using the Conners Revised Short Forms in a large twin sample. METHOD ODB data were collected from 1,595 mothers, 1,114 fathers, and 793 teachers of 7-year-old twin pairs from the Netherlands Twin Registry in the 1990-1992 cohort with an 80% response rate. Models were fit for each informant to determine the genetic, environmental, gender, and informant influences on ODB. RESULTS Genetic analyses of the ODB quantitative scale showed additive genetic (A) by mother (55%), by father (57%), and by teacher (21% girls, 38% boys) unique environmental (E) (mother, 22%; father, 29%; teacher, 48% girls, 39% boys) and shared environmental (C) (mother, 14%; father, 23%; teacher, 31% girls, 23% boys) influences. CONCLUSIONS Additive genetic and unique environmental factors account for the majority of the influences on ODB for boys and girls by all informants.