[jonno]

Do the men in these extended families participate in raising the children? Of course.

Thanks for helping to make my point.

[Nero Germanicus]

It depends on the culture. I’m sure that you are aware of the fact that in many cultures child rearing is considered “women’s work.” The nuclear family is a rather new development in the history of human civilization.

“Merriam-Webster dates the term back to 1947, while the Oxford English Dictionary has a reference to the term from 1925; thus it is relatively new.
-Wikipedia