There are many theories about why religion exists, most of them unproven. Now, in an article published in Psychological Science, a journal of the Association for Psychological Science, psychologist Kevin Rounding of Queen’s University, Ontario, offers a new idea, and some preliminary evidence to back it up. The primary purpose of religious belief is to enhance the basic cognitive process of self-control, says Rounding, which in turn promotes any number of valuable social behaviors. He ran four experiments in which he primed volunteers to think about religious matters. Those volunteers showed more discipline than controls, and more ability to delay gratification.