Two recent studies by Brandon Randolph-Seng and myself found that being reminded of religion can promote honesty. They are published in the current issue of The International Journal for the Psychology of Religion. The general format of the research involved first "priming" people with either religious words or nonreligious words, then giving them another task to perform. In Study 1, the priming involved a 'scrambled sentence' task, in which the participant unscrambled words in order to make a complete sentence. In Study 2 the priming was done subliminally, or below the threshold of conscious awareness, by displaying the word briefly (80 milliseconds) on a computer screen and then displaying a series of characters (XXXX) for another 100 ms in order to ensure that the image of the word did not persist on the screen. Following the priming task, participants were given an opportunity to complete a task that could easily involve cheating. In both studies, people who had been exposed to the religious words were less likely to cheat than were people exposed to other words. In fact, none of the people exposed to religious words cheated, but nearly half of the people exposed to other words in Study 1 (with the scrambled sentence task) cheated. In Study 2, where words were presented subliminally, 20% cheated in the group exposed to nonreligious words... and once again, none who saw the religious words cheated.
Read more about our project on this pdf copy of the article. If you are interested in this line of research, you'll also want to read this article by Shariff and Norenzayan that found religious priming resulting in increased levels of generosity.