You must remember Gustavus Adolphus, that name would put it from 1721 until now.
Yeah and Charles XII also - I forgot about him.
I guess the point is that warrior cultures like the Vikings, Romans, Anglo-Saxons, with time get castrated.
Modern day Scandinavians, Italians and Brits are nothing like their ancestors, but people of those groups living here in the U.S. are by no means wussies. WE still have manly men here - despite the liberal attemp to castrate us all.
So it is probably cultural in the case of humans rather than genetic - at least up to now.