I'm pretty sure that if our cave-man ancestors raised children the way we do, humanity would have either have gone extinct or babies would be way less annoying[

I'm pretty sure that if our cave-man ancestors raised children the way we do, humanity would have either have gone extinct or babies would be way less annoying[1] thanks to evolutionary selection. There's no way a huge percentage of stone age babies wouldn't have been shaken to death or hurled off cliffs at 2am otherwise. I'm sure some were anyway, but it'd have been most of them. It had to have been a more collective effort than it is now, with a greater relief from work for those involved in the caretaking than we enjoy. It must have been both, because even a single dedicated stay-at-home caretaker will go nuts without support/relief, and the typical working partner does not have the capacity to properly provide that at night and not be really, really messed up during the day. [1] I write this as a parent of two. Hospitals bombard new parents with "don't shake your baby" educational material. They do this because babies are phenomenally shakeable things, especially when they're shrieking for no damn reason at 2am and you're so tired from days on end of terrible sleep that you're beginning to hallucinate.