Religious people have better self-control

According to an article in the New York Times, a new study in the Psychological Bulletin suggests that people who embrace a religion have better self-control than people who do not.

I would like to know if it matters whether the religion itself requires some manner of self-control. Some religions require more self-control than others; if we compared a group whose ideals—as lived, not as lip service—were stricter than another group, which would practice greater self-control?