jgnat,
I have read the article by Haidt you reference above and found many of his arguments quite compelling. However I agree with Sam Harris conclusion in his comment:
"Religion remains the only mode of discourse that encourages grown men and women to pretend to know things they manifestly do not (and cannot) know. If ever there were an attitude at odds with science, this is it. And the faithful are encouraged to keep shouldering this unwieldy burden of falsehood and self-deception by everyone they meet---by their coreligionists, of course, and by people of differing faith, and now, with startling frequency, by scientists who claim to have no faith. Even if Haidt's reading of the liteature on morality were correct, and all this manufactured bewilderment proves to be useful in getting certain people to donate time, money, and blood to their neighbors---so what? Is science now in the business of nurturing useful delusions? Surely we can grow in altruism, and refine our ethical intuitions, and even explore the furthest reaches of human happiness, without lying to ourselves about the nature of the universe. It is time that atheist scientists, above all people on this infatuated planet, acted as if this were so."
People like to be deluded and religion gladly complies. I suggest that the surveys which show religious people as more generous than secular people also show the control that the religious group holds over its people, that perhaps people aren't donating purely for atruistic reasons but because they feel a certain amount of pressure to do so, bragging rights, if you will. Another possibility is that the surveys themselves are biased.
Reopened Mind