Comment by aksss

> conquest engrained in their cultural DNA

Perhaps nuance, but I believe the PIE people are presumed to have developed a cattle-raiding culture, which is just a raiding culture in general regardless of the wealth at hand (slaves, goods, food, etc). As an aside, I'm always fascinated by Ibn Fadlan's observation (877 AD) when going up the Volga that there was a "slaving season". That probably goes back millennia.

Anyway, in turn, some of those bands - much like the much later viking gangs - probably decided to "stay" at the places they raided, which looks a lot like conquest. Anyway, not taking away from your point, just some color. :)