Humans are social creatures—we live in community. And our individual health and wellbeing  is intricately tied to the health of our communities and our interactions with others.
Many norms and behaviors are established by the community. For example, if everyone around us is smoking, then it becomes okay to do so. When a lot of people quit, we tend to imitate them and cease smoking as well. Obesity is another “contagious” behavior. In the fascinating book Connected, Christakis cites evidence that: “the average obese person [is] more likely to have friends, friends of friends, and friends of friends of friends that were obese than would be expected due to chance.”
Thus norms and habits spread through our social networks—the ties we have to others in our community and the ties that our connections have. We are strongly influenced by these networks, but we can also influence them.
Our social networks also provide benefits, not only to ourselves, but to our community. In fact, they provide so much value that they are sometimes called “social capital.”
Social capital is the collective value of all the social networks in a community. This value arises because our networks allow us to accomplish what we can’t on our own, whether it’s finding a job, taking care of a loved one with cancer, or simply passing information quickly. They offer resources we might not be able to access on our own.
Social networks offer benefits, not just for us as individuals in the network, but for the community as a whole. As Christakis notes, they foster trust and reciprocity and facilitate the flow of altruism and generosity. Vibrant social networks contribute to the public good in the form of lower crime rates, better public health, and reduced political corruption—to mention just a few.
Robert Putnam, the author of Bowling Alone and Better Together, discusses how social capital is directly linked to individual wellbeing (which he calls subjective wellbeing) through many channels.
“Our new evidence confirms that social capital is strongly linked to subjective well-being through many independent channels and in several different forms. Marriage and family, ties to friends and neighbours, workplace ties, civic engagement (both individually and collectively), trustworthiness, and trust all appears independently and robustly related to happiness and life satisfaction, both directly and through their impact on health” (Helliwell and Putnam, 2009).
Thus, vibrant social networks are a vital part of a healthy community and individual wellbeing.
However, our social connections and capital are falling in the United States. In Bowling Alone, Robert Putnam documents this decrease: over the last 30 years, our participation in public affairs and civic associations, as well membership in churches, unions, and the somewhat symbolic bowling league, has fallen by 25 to 30%. And with that reduction also comes a decrease in charitable giving, as well as a decrease in the number of people participating in the political process and an overall dwindling of trust in others.
So it is important, if we are concerned about the wellbeing of our communities, as well as our own, that we look to strengthen our social networks.