When it comes to interpreting theÂ findings of health and lifestyle studies, there’s one axiom to keep firmly in mind:Â Correlation does not equal causation.
Got that?Â Correlation does not equal causation. In other words, just because two things appear to be associated with each other, it doesn’t necessarily meanÂ one of themÂ causedÂ the other.
This principle leaped rather strongly to mind this week after reading a new study about the impact of social relationships on mortality. The study, which was publishedÂ in the latest issue ofÂ PLoS Medicine, analyzed 148 previous studies that examined the effect of socialÂ relationships and whether peopleÂ who wereÂ well integrated sociallyÂ lived longer than those who were moreÂ isolated.
It’s an intriguing question to ask. As the study’s authors point out, there’s been a trend in industrialized nations for people to be less socially connected. It’s logical to wonder whether we’re headed inÂ the wrongÂ direction or whether increasing social isolationÂ might translate into a negative effect on physical and mental health.
After analyzing a large collection of prior studies and calculating the “effect size” ofÂ social integration on mortality risk, the researchers concluded that people with what they termed “adequate social relationships” had a “50% greater likelihood of survival compared to those with poor or insufficient social relationships.” What’s more, the effect appeared to be comparable to quitting tobacco and was even stronger than well-established risk factors such as obesity and lack of activity.
The study describes the implications:
Physicians, health professionals, educators, and the public media take risk factors such as smoking, diet and exercise seriously; the data presented here make a compelling case for social relationship factors to be added to that list. With such recognition, medical evaluations and screenings could routinely include variables of social well-being; medical care could recommend if not outright promote enhanced social connections; hospitals and clinics could involve patient support networks in implementing and monitoring treatment regimens and compliance, etc.
The authors conclude:Â “Social relationship-based interventions represent a major opportunity to enhance not only the quality of life but also survival.”
It’s all certainly very intriguing, but I’m not quiteÂ ready yet to run out and make 10 new friends just so I can tack on an extra few years of life. Despite allÂ the data and the number-crunching, this study did not demonstrate conclusively that social integration in and of itself is a protective factor against early mortality. Sure, it showed an association – but this is not the same thing as proof.
In some ways, the study actually raisedÂ more questions than it answered. How should “adequate social integration” be defined? AreÂ strong family relationships better for our health than friendships with peers? Are 10 friends better than two or three? Which is more protective – a large circle of casual acquaintances or a small handful of close friendships?
It’s entirely possible that people who are less socially integrated and die sooner are in poorer health to begin with – and that their poorer health status is the reason they aren’t as socially active. (The researchers said they controlled for this but it’s always tricky toÂ draw conclusionsÂ from multiple studies, all ofÂ which mightÂ have been designedÂ inÂ different ways.) Or maybe there’s someÂ other factor that hasn’t been accounted for, such asÂ particular physical, emotional or behavioralÂ characteristics that might influence someone’s likelihood of being both socially engaged and living longer. Perhaps social engagement isÂ aÂ surface expression of something deeper, such as a sense of personal belonging, purpose and meaning.
It’s also interesting to note the study’sÂ implicit bias: theÂ assumption that social integration is almost always beneficial and should be vigorously pursued for better health. American culture is fundamentally open and gregarious – we’re the ones who gave the world Facebook, after all – and extroversionÂ hasÂ come to beÂ viewed as the norm.Â When this is the case, people who are introverted and more comfortable withÂ solitude can be seen as not quite right or somehow in need of fixing.Â Researchers mightÂ conclude we should all be more socially engaged because it’s good for us, but an introvert could well find this stressful and not particularly beneficial to his or her well-being. In fact, more than a few social observersÂ have lamented that Americans, with their dependence on cell phones and 24/7 access to the Internet, are becoming too connected.
It all seems like an area ripe for further research. Just remember, though: If it appears that people who are more socially engaged tend to live longer, it doesn’t automatically follow that their social life is theÂ reason forÂ their longevity. Correlation does not equal causation.
West Central Tribune file photo by Bill Zimmer