Actually, I recently watched a documentary on this, and they did that experiment where newborn wolf cubs were taken from a nature preserve and hand-reared in a human home- the results were, let's just say, disastrous. A similar experiment was done using foxes captured from the wild and/or bought from fur farms, and by selectively breeding the tame foxes, within 3 generations the kits were tame enough to be held. The same held true for aggressive foxes, by the third generation the narrator called them dragons instead of foxes.
But I totally agree on the point of "when does nurture take over from nature" or the other way around, which I'm too tired to dechiper right now. It's my opinion that somehow, humans have an extra gene or something that tells them to "screw nature, obey nurture". But what exactly makes them do that?