^Thought experiment – on reciprocal Altruism:
"Imagine a species of bird that suffers from a disease carrying tick and must spend a good deal of time removing them with its beak. It can reach every part of its body but the top of its head. Every bird would benefit if some other bird groomed its head. If the birds in a group all responded to the sight of a head presented to them by grooming it, the group would prosper.
"But what would happen if a mutant presented its head for grooming but never groomed anyone else? These freeloaders would be parasite-free and could use the time they saved not grooming others to look for food. With that advantage they would eventually dominate the population, even if it made the group more vulnerable to extinction.
"One can imagine a pathetic final act in which all birds on stage present to one another heads that none will groom.
"But say a different, grudge bearing mutant arose. This mutant groomed strangers, groomed birds that in the past had groomed it, but refused to groom birds that had refused to groom it. Once a few of them had gained a toehold, these grudgers could prosper, because they would groom one another, and not pay the costs of grooming the cheaters. And once they were established, neither indiscriminate groomers nor cheaters could drive them out, though in some circumstances cheaters could lurk as a minority.
-Steven Pinker, "How the mind works", paraphrasing Richard Dawkins.
There is no real bird like this. But it demonstrates, in rather a cold, evolutionary way (which isn't my personal style but it was interesting just the same), how love of non-kin could have evolved. Of course, in humans, we're capable of going far beyond this. I don't necessarily buy into the idea of "the selfish gene" 100%, but then again, whatever happened with animals won't necessarily happen with larger mammals or people, because we are capable of playing by a different set of rules altogether… or are we? -Ken^