None of these concepts are that new: trust, information, and social network…… Why now they are so “in fashion?”
The bandwidth hypothesis – presumed in closure models of social capital and in related work such as models of reputation in economics – says that network closure enhances informations flow. The echo hypothesis – based on the social psychology of selective disclosure in informal conversations — says that closed networks do not enhance information flow so much as they create an echo that reinforces predispositions.
Bandwidth and echo represent a fundamental choice for theoretical models of trust and its correlates. Down the bandwidth path of network closure improving information flow lies theory in which people are better off when strongly connected to each other. Here lies stories about closed networks providing social capital and reputation.
Alternatively, the path assuming echo leads to theory in which perception drift away from empirical reality, and what closed network produce is ignorant certainty. Here lies stories about scapegoating, groupthink, and distorted reputations defined by polarized trust and distrust in closed networks.
Network closure does not facilitate trust so much as it amplifies predispositions, creating a structural arthritis in which people cannot learn what they do not already know.