It's popular these days to talk of social tribes, selfish genes, and memes blindly propgating to survive; but ultimately it's humanity's ability to consciously overide our genetic instincts which has built modern civilisation.

Over the last few thousand years our tribes have grown and blurred, and communities have evolved around common perceptions of fairness, justice and equality -- we're no longer completely controlled by short term survivalist instincts, we take actions and make choices that will further the development of our civilisation as a whole.

I'd like to think that the generosity and community found here (and in many other online communities) does not simply arise out of a selfish expectation to be paid back at some later time for the assistance being offered, but rather a fundamental appreciation that the health and wellbeing of each element contributes directly to the flourishing of the perl tribe, and our ability to crush that neanderthal php tribe... (um... hang on a minute...) :)