A thought.
I cannot think of a more common example of collective altruism than driving.
Despite the fact that everyone is going somewhere, and usually would do better to get there faster, there is an immense amount of selfless regard for other drivers on the road.
Think about it. Every time I have been stuck in a shitty lane, someone (eventually) lets me in, even though this will only make his drive longer. Still I dare-say most people have done it at least once. Moreover, there is no reward for such good behavior. In fact, the best one can hope for is a polite wave from a person you never saw and probably never will again. I mean, if you compare driving in traffic to waiting in line, then this behavior is ridiculous. Rarely does anyone let someone else cut him in line, it pisses off everyone behind you and yet it is courteous and not uncommon practice on the road.
So kudos to drivers. Funny how the cause of so much rage is also such a good source of altruism.