The central premise of the social capital approach is that social networks have value. Social capital refers to the collective value of all social networks and the inclinations that arise from these networks to do things for each other [that is, norms of reciprocity]. The term “social capital” encompasses not just warm, cuddly feelings, but a wide variety of quite specific benefits that flow from the trust, reciprocity, information, and cooperation associated with social networks. Social capital creates value for the people who are connected and often for bystanders as well. That is, social networks have both internal and external consequences.
Putnam, Robert D. "How Bowling Alone Leads to Aging Alone: Social Capital in the Later Years of Life." Statement Before the Joint Economic Committee of US House and Senate Hearing, May 17, 2017.