Comment by AtlasBarfed

However, consider the environment, quite hostile, where being a part of the tribe is about as starkly life-or-death as it gets. Stay with the tribe in the deep of winter: you live. Get chucked out for a couple hours in the deep cold (and I mean ... COLD) and you're dead in hours.

Yet southern populations of people always have reputations for being hotheaded, but northerners (stoic scandinavians) have the opposite.

It could be this one trick you click, but it could also be rapacious evolutionary and social evolutionary pressure imposed by nature.