People with average or large social networks, in the top 50 to 30 percent, lived longer than those in the lowest 10 – a finding consistent with classic studies of offline relationships and longevity.
Those on Facebook with highest levels of offline social integration – as measured by posting more photos, which suggests face-to-face social activity – have the greatest longevity. Online-only social interactions, like writing wall posts and messages, showed a nonlinear relationship: Moderate levels were associated with the lowest mortality.
Because the researchers were studying an online social network, they could also look at the direction of friendship requests. It was Facebook users who accepted the most friendships who lived the longest. There was no observable relationship for those who initiated the most. This finding was a little disappointing, the researchers note, because it suggests that public health interventions urging people to go out and try to make more friends may have no effect on health.
Does it also suggest that being “popular” makes you live longer? Maybe. According to both Hobbs and Fowler, it’s hard to say which way that goes. It could be that individuals who are more likely to live longer are more attractive to others in the first place. That, as they say, needs more research.
“The association between longevity and social networks was identified by Lisa Berkman in 1979 and has been replicated hundreds of times since,” said Fowler. “In fact, a recent meta-analysis suggests the connection may be very strong. Social relationships seem to be as predictive of lifespan as smoking, and more predictive than obesity and physical inactivity. We’re adding to that conversation by showing that online relationships are associated with longevity, too.”
The researchers would like to see their associational study, like Berkman’s seminal one, inspire many follow-ups. They hope that subsequent research leads to a better understanding of what kinds of online social experiences are protective of health.
“What happens on Facebook and other social networks is very likely important,” Fowler said. “But what we can’t do at this time is give either individual or larger policy recommendations based on this first work.”
Hobbs and Fowler’s co-authors on the paper are Moira Burke of Facebook and Nicholas Christakis of Yale University.
The project was reviewed and approved by UC San Diego’s Institutional Review Board, California’s Committee for the Protection of Human Subjects, and the Vital Statistics Advisory Committee at the California Department of Public Health.
