Even if we consider ourselves part of a more refined segment of civilization, the pleasure we supposedly seek for others (as we desperately try to appease our consciences) is really to please ourselves as we fancy ourselves as “selfless”– in the hopes of somehow pushing along a sort of human social evolution – all the while seeking our own smug satisfaction. If we don’t take pride in our individual self, we take it in our kind.

Sexual arousal, for instance, presumably evolved because of its connection to making babies; but of course we can get aroused in all sorts of situations in which baby-making just isn’t an option — for instance, while looking at pornography. Similarly, our impulse to help others has likely evolved because of the reproductive benefit that it gives us in certain contexts — and it’s not a problem for this argument that some acts of niceness that people perform don’t provide this sort of benefit. (And for what it’s worth, giving up a bus seat for an old lady, although the motives might be psychologically pure, turns out to be a coldbloodedly smart move from a Darwinian standpoint, an easy way to show off yourself as an attractively good person.)

-http://www.nytimes.com/2010/05/09/magazine/09babies-t.html?pagewanted=all&_r=0