Twin Differences in Harsh Parenting Predict Youth's Antisocial Behavior

In the current study, we leveraged differences within twin pairs to examine whether harsh parenting is associated with children's antisocial behavior via environmental (vs. genetic) transmission. We examined two independent samples from the Michigan State University Twin Registry. Our primary sample contained 1,030 families (2,060 twin children; 49% female; 6-10 years old) oversampled for exposure to disadvantage. Our replication sample included 240 families (480 twin children; 50% female; 6-15 years old). Co-twin control analyses were conducted using a specification-curve framework, an exhaustive modeling approach in which all reasonable analytic specifications of the data are interrogated. Results revealed that, regardless of zygosity, the twin experiencing harsher parenting exhibited more antisocial behavior. These effects were robust across multiple operationalizations and informant reports of both harsh parenting and antisocial behavior with only a few exceptions. Results indicate that the association between harsh parenting and children's antisocial behavior is, to a large degree, environmental in origin.