Nested model fitting results confirmed results from the full model. Path n could be dropped without a decrement in model fit but path m could not (see Table 1). Dropping each of the non-significant paths separately or together did not result in a decrement in model fit. The most parsimonious model included effects of A1, E1, m, and A2. Direct environmental influences of parental knowledge on adolescents’ externalizing explained the correlation between parental knowledge and adolescent externalizing.