Robert Sapolsky

It can be far more than a mere academic matter when a scientist thinks that human behavior can be entirely explained from only one perspective.

For example, being raised by a single mother increases the risk of adult antisocial behavior, but not because of the parenting; instead, because of typically lower income, kids more likely live in a neighborhood with tough peers. (b) Peers have impact on linguistic development

Parental influence is often actually mediated via peers.