Hands up, anyone who wants to take a guess. What is the biggest risk factor for illness in modern times? Smoking? Big Macs? Alcohol? All of them in excess aren’t very good for you, that’s for sure, but they may not offer the health risks of one simple facet of modern life: being by yourself a bit too much.

Loneliness and isolation are not just regrettable social situations; they’re killers. They distort brain function, causing hallucinations and depression. They’re the equivalent of smoking 15 cigarettes a day—worse for you than being obese, breathing polluted air or even being a couch potato.

Deep connection, rather than competition, is the quality most essential to human nature, and it’s one reason the Covid lockdowns were such a disastrous policy, far more dangerous and long-lasting than the virus itself.

Humanity is profoundly tribal; we feel most at home in small clusters in which we are a part of the whole. This most primal of human urges—not to stand apart but to connect, particularly with the people who immediately surround us—may well be so necessary to our existence that not satisfying it can be a matter of life or death.

At the University of California, Berkeley, sociologist Lisa Berkman once examined the importance of social networks and social support in protection against heart disease. She assembled the health statistics of most inhabitants within an entire county by laboriously combing through nine years’ worth of Alameda County Human Population Laboratory records.

Eventually she was able to show that those who felt lonely and isolated socially were two to three times more likely to die from heart disease and other causes than those who felt connected to others. These results were independent of risk factors such as high cholesterol levels or high blood pressure, smoking, and family history.

As Berkman was fascinated to learn, our biological responses to stress—the fight-or-flight mechanisms of our autonomic nervous and endocrine systems—are subdued when a companion is present, when we believe support will be present or even when we just think about support.

And that can act like a bulletproof shield. For instance, a group of researchers studying the native populations of the Solomon Islands found they had no coronary heart disease or high blood pressure even after adopting Western diets and religious practices. This puzzled the researchers until they discovered the one factor that had remained constant: the social ties and roles within the family.

In that sense, heart disease can be viewed chiefly as a disease of emotional alienation. Healthy adults with good support networks have been shown to have lower blood cholesterol and stronger immune function than those without emotional support.

A similar situation occurs with stroke patients; those who are socially isolated are more likely to have another stroke within five years.

Brigham Young University data from 148 studies came to an equally stark conclusion; relationships of any sort—good or bad—improve your odds of survival by 50 percent. Isolation was equivalent to smoking 15 cigarettes a day or being an alcoholic and was twice as harmful as obesity.

These sorts of social connections even protect us in hard times. As one study showed, a sampling of Americans in the lowest income bracket suffered from virtually no stress about their financial circumstances so long as they had two means of support: a strong spiritual connection and a strong community.

The community connection was even more important than their spiritual beliefs; private prayer was not as protective as the support of their church group. Even when engaged in a daily struggle to survive, they were able to manage as long as they didn’t do so alone.

This protection starts early. A close family structure and strong community support during childhood have been found to offer life-long protection against future heart disease and other illnesses.

As a simple antidote to the ever-increasing isolation of modern times, membership in social groups of every variety can act as one of nature’s best preventive medicines. Social psychologists at the UK’s University of Exeter discovered that the most important predictor of health—even more than diet and exercise—is the number of groups to which you belong, particularly if you have strong relationships within them.

“As a rough rule of thumb,” writes Harvard political scientist Robert D. Putnam in his book Bowling Alone (Touchstone Books, 2000), “if you belong to no groups but decide to join one, you cut your risk of dying over the next year in half.”

The prescription against future illness of many varieties is simple:  join a group – a bowling group, book group, religious group, my community and especially a Power of Eight® group—and you immeasurably increase your chances of living a long and healthy life.