Why does self-reliance make you sick?

Newspapers used to run occasional human interest stories about very old people dying. These profiles often had a subtext, which went something like this: So-and-so died yesterday at the age of 102, and remained fiercely ornery and independent to the end. He never took very good care of himself, smoking two packs a day since he was a teenager. He liked his whiskey.

You don’t see these stories nearly so much anymore. That’s in part because living past 100 isn’t all that uncommon anymore, but it’s more than that. In our hearts, we knew all along that these misbehaving centenarians were aberrations. Plus our sensibilities about public health have shifted, so that journalists don’t romanticize unhealthy habits so much anymore. The fact is that smoking and excessive drinking don’t prolong life; they shorten life and diminish its quality.

That’s true of the “fiercely independent” part, too. Health psychologists have known for years that isolation is rarely the path to health or longevity. Health comes with a rich and diverse social life, with lots of friends and family, church membership and political engagement. Old people with many relationships of different kinds live longer, stay sharper with age, and suffer less disease.

But why? What is it about being connected to others that makes us healthier and more long-lived? How does a rich social life translate into healthy cells and tissues, and conversely, how does isolation trigger the biological processes of disease and death?

What we know so far. Carnegie Mellon psychologists Sheldon Cohen and Denise Janicki-Deverts have been studying these questions, and in the July issue of Perspectives on Psychological Science they provide a progress report. Here’s the gist:

The evidence so far is what scientists call “correlational,” which means that it doesn’t really say anything whatsoever about cause and effect. It may be clear that socially integrated people are far healthier than isolated people, but that doesn’t mean a rich social life causes better health. It could very well be that healthier people feel more like being around other people, and people who feel lousy simply prefer to be alone. This needs to be sorted out.

One way to sort this out is to actually intervene in people’s lives--enrich their social lives and see what happens. But this isn’t easy to do. Scientists can’t really tell people to join the Rotary or to reconcile with estranged love ones. As a result, interventions haven’t been done much, and the ones that have been done mostly put people together with others facing the same challenge, like cancer. These interventions have had mixed results at best.

What lies ahead. So the existing studies leave a lot of questions begging for answers: For example, do socially connected people have particular psychological traits that help them cope with disease, or avoid it? Do they have different expectations or world views? Are they more optimistic, trusting, or confident? Do they help others more, and could that selflessness have health consequences? Are they more capable of regulating their emotions? How about the group itself: Is the diversity more important than the sheer numbers, or the other way around?

And what can be done to help? Perhaps there are ways to reunite estranged family members, if that is proven to mitigate loneliness and improve health. Or maybe the elderly can be encouraged to join social or recreational groups. Perhaps some basic social skills training would give people the psychological tools to connect more on their own.

It’s also possible that that people’s perceptions of their social connections are more important than the actual details of their lives, so that therapeutic interventions might target how people think. One study of this type did bolster people’s sense of being supported, but it didn’t have any appreciable effect on health and disease. And that, of course, is what matters in the end: how social networks “get under our skin” to influence disease and mortality.