The Developmental Propensity Model Extends to Oppositional Defiant Disorder: a Twin Study.

Previous research has supported the developmental propensity model, which proposes that three socioemotional dispositions (prosociality, negative emotionality, and daring) increase risk for the development of conduct problems through shared genetic and environmental influences. The current study extends this research by examining the model in relation to oppositional defiant disorder (ODD). Based on a confirmatory factor analysis, ODD was examined as three separate dimensions (irritable, headstrong, and hurtful) rather than a unitary construct. Parents of 686 same-sex twins (ages 7-13) provided ratings of their twins' dispositions and ODD symptoms. Results from a path model examining phenotypic relationships showed that all dispositions were significantly related to each ODD dimension, except daring was not predictive of the irritable dimension. Preliminary twin analyses showed nonadditive genetic effects only on daring, which limited the appropriateness of evaluating it with the other dispositions. Results from a series of models used to examine etiological associations showed all ODD dimensions had common additive genetic influences with prosociality and negative emotionality. Only headstrong had common additive genetic influences with daring. Irritable and headstrong had common shared environmental influences with respect for rules (an aspect of prosociality), and common nonshared environmental influences with negative emotionality. Hurtful showed no shared environmental influences, but it had common nonshared environmental influences with prosociality and negative emotionality. These findings support the idea that the socioemotional dispositions in the developmental propensity model have some common etiological influences with ODD dimensions, suggesting this model can provide a novel framework for understanding the development of ODD.