Social capital is the value of social groups and the support and benefits to and individual of interpersonal relationships, and a shared sense of identity, a shared understanding, shared norms, shared values, trust, cooperation, and reciprocity. An example might be the advantages of being part of a large family or supportive community. The 'old school tie' is a term which refers to the support which individuals might have from those who went to the same school or share the values that you school represents. Network and community form our social capital.
In his book Bowling Alone, Robert Putnam discusses ways in which Americans have disengaged from political involvement including decreased voter turnout, attendance at public meetings, service on committees, and work with political parties. Putnam also cites Americans' growing distrust in their government. Putnam accepts the possibility that this lack of trust could be attributed to "the long litany of political tragedies and scandals since the 1960s",but believes that this explanation is limited when viewing it alongside other "trends in civic engagement of a wider sort".
Putnam notes the aggregate loss in membership and number of volunteers in many existing civic organizations such as religious groups (Knights of Columbus, B'nai Brith, etc.), labor unions, parent–teacher associations, Federation of Women's Clubs, League of Women Voters, military veterans' organizations, volunteers with Boy Scouts and the Red Cross, and fraternal organizations (Lions Clubs, Benevolent and Protective Order of Elks, United States Junior Chamber, Freemasonry, Rotary, Kiwanis, etc.). Putnam uses bowling as an example to illustrate this. Although the number of people who bowl has increased in the last 20 years, the number of people who bowl in leagues has decreased. If people bowl alone, they do not participate in social interaction and civic discussions that might occur in a league environment.
He then asks the obvious question "Why is US social capital eroding?" and discusses several possible causes. He believes that the "movement of women into the workforce" and other demographic changes have had an impact on the number of individuals engaging in civic associations. He also discusses the "re-potting hypothesis", that people become less engaged when they frequently move towns, but finds that Americans move towns less frequently than in previous decades. He does suggest that suburbanization, economics and time pressures had some effect, though he notes that average working hours have shortened.
n their 2017 book One Nation After Trump, Thomas E. Mann, Norm Ornstein and E. J. Dionne wrote that the decline of social and civic groups that Putnam documented was a factor in the election of Donald Trump as "many rallied to him out of a yearning for forms of community and solidarity that they sense have been lost