God to Jesus. I just condemned the human race. Now go die to save them.

[Angrboda]

J.B.S. Haldane, when asked whether he would risk his life to save a brother famously replied, "No, but for two brothers or eight cousins." This form of altruism is based on the well known kinship selection effect. Those who are closely related to us likely share most of our genetic heritage, thus sacrificing myself for two kin furthers both my specific genetic heritage but also the propensity to sacrifice myself in the interest of two kin (as that is as much a part of my genetic heritage, which they share, as eye color).

Now I'm not suggesting that all examples of altruism are due to kinship selection, but it points out that the "motives" for actions aren't always sitting there on the surface of an example, waiting for us to pluck them off. That there is no obvious (selfish) explanation is not the same thing as there not being an explanation. As pointed out before, and often honored in the breach, assuming that any explanation lies in the set of explanations you have at hand is a misapplication of the law of the excluded middle, as there may always be explanations that you don't know about because you don't know about them.

And as has been pointed out before, my pistol whipping my neighbor doesn't make my son more virtuous or absolve him of any crimes.