'Religions are moral exoskeletons. If you live in a religious community, you are enmeshed in a set of norms, relationships, and institutions that work primarily on the elephant to influence your behavior. But if you are an atheist living in a looser community with a less binding moral matrix, you might have to reply somewhat more on an internal moral compass, read by the rider. That might sound appealing to rationalists, but it is also a recipe for anomie - Durkheim's word for what happens to a society that no longer has a shared moral order. (It means, literally, "normlessness."). We evolved to live, trade, and trust within shared moral matrices. When societies lose their grip on individuals, allowing all to do as they please, the result is often a decrease in happiness and increase in suicide, as Durkheim showed more than a hundred years ago.
Societies that forgo the exoskeleton of religion should reflect carefully on what will happen to them over several generations. We don't really know, because the first atheistic societies have only emerged in Europe in the last few decades. They are the least efficient societies ever know at turning resources (of which they have a lot) into offspring (of which they have few).'
Jonathan Haidt, The Righteous Mind, p.313.
