When it comes to hand to hand or martial combat such as in MMA or boxing, it’s hard to guess who the winner is if you based it purely off appearance or their upbringing. There is the stereotype that people that come from “hard” areas are naturally better. While coming from certain areas give you the mindsets, the reason why good boxers come from these areas frequently isn’t because they are naturally like that, but rather they are trained.
While coming from a tough environment may give you experience over a more pampered environment, it still pales to what real training gives you. That’s why the “hard” person does not always win against the fellow untrained, because the skill gap is not so large that it would be one sided every time.