Ilkka Pyysiäinen and Marc Hauser have co-written an interesting paper The Origins of Religion: Evolved adaptation or by-product? Jerry Coyne has a good commentary over at WEIT and raises an interesting objection by Phillip Ball that suggests a culture steeped in religious morality may present it even by people who do not subscribe to the religion itself. Jerry has posted a response to that objection from Ilkka:
As far as we are dealing with people’s intuitive judgments, it is impossible to attribute these to learned religious views. People just do not respond in accordance with religious doctrines when they have no clue about how learned religious doctrines should be applied. I think Marc’s research shows that religious doctrines can only have an effect on especially salient topics such as abortion. When religious commitments differ and people yet produce quite similar judgments, this shows that religious commitments do not have causal power with regard to moral judgment. If religious people make moral judgments similar to those of nonreligious people, then there is no reason to suppose that religion is the driving force. This means that *explicit* religious commitment is not relevant. But, as you suggest, it might still be that religion affects explicitly nonreligious people’s judgments in an implicit way. However, this, then, means that explicit religious commitment is not the crucial factor.
Try the Moral Sense Test for yourself. You won’t come across typical moral issues commonly attributed to religious teachings but it will get you wondering why you answer the way you do.