Commentary: Bonding, bridging, and linking—but still not much going on

Abstract
Much has been said about social capital and its association (if any) with health. And a common plea is to return to the theoretical underpinning of social capital, and why and how it might be associated with various outcomes including health. Szretzer and Woolcock have proposed a possible step forward in the conceptualization of social capital, arguing that there may be ‘linking’ forms of social capital in addition to previously recognized ‘bonding’ and ‘bridging’ forms of social capital.1 Bonding social capital refers to trusting and co-operative relations between members of a network who are similar in a socio-demographic sense, and bridging social capital comprises relations of respect and mutuality between people who are dissimilar. Linking social capital is ‘norms of respect and networks of trusting relationships between people who are interacting across explicit, formal, or institutionalized power or authority gradients in society’.1 For example, citizens' interactions with local government and health planning authorities are representative of linking social capital.