Coleman, Putnam, and others say trust is social capital, or an element of social capital. It appears, however, that the core of the meaning of social capital in the work of these scholars is not trust but rather the social relationships, or the networks of such relationships (as emphasized by Brehm and Rahn), that enable us to undertake cooperative endeavors. These relationships, of course, ground trust among the participants in them. They do so because we have incentive to be trustworthy to those in our networks, therefore making it beneficial to us to trust one another in various undertakings. Hence it seems wrong to think of the trust itself as an element of social capital.

Russell Hardin, Trust and Trustworthiness, loc. 409