A study recently reported in Demography found that whites who attended religious services more than once a week lived an average of 7 years longer than whites who didn’t attend services at all; among blacks, the figure was 14 years. The churchgoers’ lower rates of smoking and drinking certainly account for some of this gain, but their strong social ties and other behavioral factors may also play a role, says Robert A. Hummer, Ph.D., a sociologist at the University of Texas.