I legit wonder if external factor (environment) heavily influence a population's mental growth. I mean, in deep forestry tribes, most of them are having sexual intercourse as young as 12 year old. I don't know if that's because they're so primitive that all they can think of is just mating and surviving or what. If environment does sure bring some effect (e.g. subconsciously being influenced slowly from people's actions on public, internet, TV shows, magazines, etc). Back then, information doesn't go and come super quick. That, and maybe how people commonly behave. We know there are conservative and liberal people. Not getting the political aspect since that's not why I brought these two up, but those two have opposing view (typically) on especially family things and relationship between male and female.