The afterlife isn’t the only thing atheists are missing out on by not believing in God: A new study finds that religious people live longer than nonbelievers.
Researchers at Ohio State University found that religious people live an average of four years longer than atheists. Their study was published Wednesday in the journal Social Psychological and Personality Science.
Laura Wallace, the study’s lead author and a doctoral psychology student at Ohio State, said the effect that religion has on life span is comparable to that of gender.
“Religious affiliation had nearly as strong an effect on longevity as gender does, which is a matter of years of life,” Ms. Wallace said in a statement.
Researchers examined two samples of more than 1,600 obituaries published between 2010 and 2012, looking for mentions of the deceased’s marital status, religion and the social activities in which he or she participated.
The first sample, consisting of 505 obituaries published in the Des Moines Register between January and February 2012, found that religious people lived 9.45 years longer than atheists on average. After accounting for gender and marital status, researchers found that people of faith still lived an average of 6.48 years longer than those without faith.
The second sample included 1,096 obituaries published by newspapers in 42 major U.S. cities between August 2010 and August 2011. In those obituaries, religious people lived an average of 5.64 years longer than atheists. When controlled for gender and marital status, the life span gap shrank to 3.82 years.
There are several theories as to why religion increases life span.
Baldwin Way, associate professor of psychology at Ohio State and co-author of the study, said religious strictures on unhealthy practices — like alcohol, drugs and sex with multiple partners — may explain the findings in part.
Many religions also “promote stress-reducing practices that may improve health, such as gratitude, prayer or meditation,” Mr. Way said in a statement.
The study also looked at how much of an effect social engagement had on longevity.
Previous research has shown that sociability contributes to longer life, but that was only part of the reason religious people lived longer in the study published Wednesday.
“We found that volunteerism and involvement in social organizations only accounted for a little less than one year of the longevity boost that religious affiliation provided,” Ms. Wallace said.
Researchers also said there is a “spillover effect” in which nonbelievers in highly religious cities receive some of the health benefits of faith.
“The positive health effects of religion spill over to the nonreligious in some specific situations,” Ms. Wallace said. “The spillover effect only occurs in highly religious cities that aren’t too concerned about everyone conforming to the same norms. In those areas, non-religious people tend to live as long as do religious people.”
The study builds on others that have shown religion has a positive effect on health.
There are limitations to studying obituaries, Mr. Way said, such as the inability to control for factors like race and risk-taking. A potential strength of the study is that, unlike other studies, religious affiliation was not self-reported, but reported by the obituary writer.
Ms. Wallace said there is still a lot of work to be done to understand the effect of faith on health.
“There’s still a lot of the benefit of religious affiliation that this can’t explain,” she said.