To call this emergent behavior probably sullies the point; it certainly misses it. The example has become almost archetypical to me, and as such I find it creeping out of the shadowy world of edge-cases and presenting itself as a functional explanatory rule more and more frequently. While I don't believe that humans are inherently evil, I do feel that we're inherently flawed and have, metaphorically speaking, jagged personal borders. When there's sufficient intervening space, our own personal geometries don't enter into the cultural logic.
Anchorage at midwinter: moose everywhere, driven townward by the snows. Simple, short-tempered and dense. They'll stand stupidly at the side of the road, watching automobiles slowly make their way along the icy thoroughfare, and at the last second meander out in front of them. The design is ergonomically perverse in the extreme: the front bumper clips them at the knee, which buckles, sending a quarter ton of dead weight onto the hood and through the windshield. About fifty times a winter. These things happen at the interface between man and beast. The beast probably can't help it any more than the man can.