[sunderw]

That's interesting.

A little nitpick : you seem to imply that buying a book is having an influence on parenting skills. I'd argue that's its correlated but does not have a direct influence.

As you said, if you're buying a book it means you're ready for self-reflection, which is what has an impact on parenting.

[mlrtime]

I'm fairly sure they are referring to a Freakonomics episode (or book). The researchers found "successful" parents, then found various statistics around them.

One of the conclusions was that they "type" of people that would go out of their way to buy a parenting book were already the type of people to do the "right thing" when parenting and the book itself offered no additional support.