If science could show that we have an evolved predisposition to believe in God, or gods, how would that change the debate?Religion is a feature of all human societies. Some people argue that without it, there could be no society: that belief in the supernatural expresses or dramatises some of the instincts we need to have to live in reasonably harmonious groups. Suppose science were able to prove this was true. What would it matter? Would it mean that we could then outgrow religion, understanding the cognitive and emotional illusions that give rise to it? Or should atheists resist the idea, because cognitive and emotional illusions are so deeply embedded in us that they are almost impossible to outgrow? Should believers suppose that the existence of an evolved hunger in us is an argument that the object of this hunger must somewhere and in some sense exist?