Fatherless boys and respect – what is the real issue?

Found on the Internet: “We need more boys to grow up with fathers – then they are much more likely to know how to treat a woman with respect.”

What is cause, and what is effect here?

Is it:

Men are respectful towards partners, and if women just stay with them, boys see respect and behave better?

OR

Women generally stay with respectful men and leave disrespectful ones, so the boys who from 2-parent homes are more likely to see respect modelled by respecful fathers?

I think the latter.