Researchers examined the relationship between resistance to infection and diverse social ties, including those with family, neighbors, friends, coworkers, and community members. Study participants with more types of social ties were more resistant to common colds and had fewer cold symptoms than those with fewer social ties. Those with fewer types of social relationships (one to three) were more than four times as likely to be infected with a cold virus than those with at least six types of relationships.

JAMA 1997;277:1940-1944