I wondered how other men discovered that their neighbor is having better time with his wife on the missionary position.
Missionary position was a huge innovation for humans survival. That position improved reproduction success, and much more. Couples using that position have higher chance of reproduction.
The animal like position from the back was the most common one, until a strong man but with a small joystick frustrated turned by force his partner on her back, and Succeeded to have a good time.
It’s was an awful moment in history. Very barbaric indeed. An animal, let alone a human on its back is either dead, defeated or wounded. Therefore putting his partner on her back was a historical barbaric moment. Only a strong man could have done that.
Fortunately, the lady noticed that that position was less painful for her legs and back, and for the first time she felt something deeper inside her and enjoyed it. Furthermore she got pregnant faster than her fellows, triggering envy from other ladies.
Such a lucky conjonction, led to a viral gossip among women about the new position in the jungle. Other ladies started requesting that position.
Thus, the missionary position become a fashion, which never faded.
Civilization is overrated. Without barbarism there is no evolution. It always takes strong men with small dick to make history.