LittleRedDragon doesn't it ever strike you that only sexually active women have babies? [note: I'm copying your sentence construction there so as not to be patronising
!]
Don't you think that that simple fact is observable over thousands of years to family groups? Animals which mate have babies. Animals which don't mate, through youth or social restrictions or other circumstances, don't have babies. It's really not rocket science to any family group if you think about it. Let's say the male of a couple dies. Lo and behold the female stops having babies. In the same family, a teenage girl mates and has a baby. Imagine that happening thousands and thousands of times to groups of people. Don't you think it would eventually become obvious?
That's without the dawning ability to breed livestock!
The fact that our grandmothers were ignorant of the mechanics of sex does not mean that pre-industrial, living-in-nature hunter gatherers were.
How to state those simple ideas without being called patronising? It's not patronising to point out something obvious. But lots of people are taking that personally.
I've been accused of having a bad day, of getting worked up, of trying to 'win' (WTF I think that was another poster who said 'draw'?), of being patronising and rude for saying (gasp) 'Jeez'. I do think there have been a lot of over-sensitive posters on this thread who took exception to my observation that it's a stupid question and are running rings around themselves to prove it isn't (periods are a modern phenomenon roffle!).
And STILL people want to prove me wrong! Fair enough. If this post hasn't helped you understand, I'm not sure what will. Maybe MN can invite an anthropologist for a webchat? Or some of you could look it up.
I could have been lots more patronising than that. Think yourselves lucky.