Being in meaningful relationships is life-giving in the most literal sense.

One of the most thorough research projects on relationships is called the Alameda County Study. Headed by a Harvard social scientist, it tracked the lives of 7,000 people over nine years. Researchers found that the most isolated people were three times more likely to die than those with strong relational connections.

People who had bad health habits (such as smoking, poor eating habits, obesity, or alcohol use) but strong social ties lived significantly longer than people who had great health habits but were isolated. In other words, it is better to eat Twinkies with good friends than to eat broccoli alone. Harvard researcher Robert Putnam notes that if you belong to no groups but decide to join one, “you cut your risk of dying over the next year in half.”

For another study, as reported in the Journal of the American Medical Association, 276 volunteers were infected with a virus that produces the common cold. The study found that people with strong emotional connections did four times better fighting off illness than those who were more isolated. These people were less susceptible to colds, had less virus, and produced significantly less mucous than relationally isolated subjects. (I’m not making this up. They produced less mucous. This means it is literally true: Unfriendly people are snottier than friendly people.)

Yet, we are becoming increasingly disconnected from each other. This is the thesis of the most in-depth study of contemporary society done in a few decades. Robert Putnam took the title of his book, Bowling Alone, from the fact that while more people than ever are bowling these days, fewer are doing it in leagues. He and a team of researchers documented that for twenty-five years American society has experienced a steady decline of what sociologists call social capital—a sense of connectedness and community. (This was illustrated by, among other things, the T-shirt slogan that the Volunteer Fire Department in Gold Beach, Oregon, used to promote their annual fund-raising event: “Come to our breakfast, we’ll come to your fire.”) Whether it’s measured by civic involvement, volunteer organizations, neighborhood relationships, or religious participation, Putnam found, the level of community in America is at its lowest point in our lifetimes, and this loss of social capital results in lower educational performance, more teen pregnancy, greater depression, and higher crime rates.

John Ortberg, Everybody’s Normal till You Get to Know Them (Grand Rapids, MI: Zondervan, 2009).