Predator avoidance doesn't require as long-term a thought process as winter preparation. Though the one thing I don't get about this kind of argument is why aren't the Indians (feather, not dot) geniuses? Their winters are worse than Europe's, but they're infamous for "Typical Nigger Behaviour". Is it because Europe has more hills and therefore selects for people who have the spatial intelligence to use the terrain to their advantage and the planning to place settlements optimally? Tibetans and Nepali have both factors going for them as well, but still got stuck in the Iron Age when the Europeans found them, and came up with prayer wheels, the most comically "missing-the-point of the exercise" invention I can think of. The Mediterranean rewarding cultures that develop shipbuilding, navigation skills, and the ability to quickly adopt inventions from other cultures on the same trade route? Ok, all 3 of these factors at once is pretty unique on the continental scale. It's starting to sound an awful lot like the Guns, Germs & Steel hypothesis except with biological evolution rather than cultural.