“Hundreds of studies” have found an association between religiosity and health or well-being, observes Harvard biostatistician and epidemiologist, Tyler VanderWeele in a forthcoming chapter. But “only a very small number” have rigorously examined causality. If people who worship regularly are healthier or less depressed (which they tend to be), is that because religious engagement promotes health and well-being, or because healthy, buoyant people more often leave their homes to worship?
To discern causality, new studies are assessing people’s health, their religiosity, and other health predictors, and then following them through time—for 20 years among 74,534 women in one Nurses Health Study. When controlling for various health risk factors, those who attended services more than weekly were a third less likely to have died than were non-attenders. In another analysis, the same comparison yielded a “5-fold lower rate of suicide.”
These and other such findings lead VanderWeele to conclude that “religious participation . . . is a powerful social determinant of health.”
But why? Unpacking the religiosity variable, VanderWeele and his colleagues, in the mortality study, report that social support explained 23 percent of the religiosity effect, not smoking explained 22 percent, less depressive symptoms explained 11 percent, and optimism 9 percent. People who are active in faith communities experience more social support, smoke less, are less depressed, and are more optimistic than are those not active in such communities.