Well obviously we don't like this anymore. I'm merely explaining why it was a thing in the early ages and in no way am I trying to imply going back to such things.thus a biological need to get knocked up at 15-16-17 is dubious
I think this is wrong actually. People specifically had a shit load of kids, as many as possible actually, the reason being....the more kids you had, the more help you had in the tribe/farm/higher chance your family continues for future generations.Nobody had a plan like "maybe 3 kids, two girls and a boy" like they nowadays might.
I guess people didn't "plan" for it the way you imply. But I would argue that most people don't plan out their family in that way the way they used too in the 1950's.
But all of that is beyond the scope of this discussion, though it does help the argument of showing how different people are between the sexes and the reasons behind all of it.