Regarding this one:
> Sex probably includes factors of better sexual education. Higher pregnancy rates are seen in populations with no or bad sexual education. Also, you are 'held to the fire' by the state if you get someone pregnant.
It's possible that the easy availability of porn has a lot more to do with this than just fear of pregnancy, which is probably why this is seen across the board (urban, rural, ethnicities, etc) and despite apps like Tinder.