There is no evidence that having married parents is a significant factor. Correlatiod does not equal causation. Parental education and income levels, and age, also have very strong correlations to children's behavior and eventual educational achievement and criminality. And I don't think it would be hard to prove that parental rap sheet length is one of the strongest predictors for out of control children who grow up to engage in criminal behavior. On the other hand, you'll find very good outcomes among children of financially self-sufficient single parents. Outcomes for children raised only by their widowed mothers, when the father died before or shortly after the chidren's birth, are indistinguishable from those of children raised in 2-parent homes, exposing the falsehood of the notion that lack of a father is a major causative factor of poor outcomes for children.
The effects of the "feminization" of the American male is something I must deal with everyday.