Echo Chambers and Homophily in the Diffusion of GMO Risk Information

This chapter investigates the mechanisms underlying the diffusion of risk information about GMOs on Weibo. Drawing upon social contagion theory, this chapter examines how endogenous and exogenous mechanisms shape users’ information-sharing behaviors. An analysis of 388,722 reposts from 2,444 original GMO risk-related texts enabled the construction of a comprehensive risk information-sharing network with computational text-mining techniques employed to detect users’ attitudes toward GMOs. To bridge the gap between descriptive and inferential network analysis, this chapter employs a Shannon entropy-based approach to quantify the uncertainty and concentration of attitudinal differences and similarities among sharing and non-sharing dyads. The analysis revealed that information-sharing ties are characterized by lower entropy in attitude differences. This indicates greater attitudinal alignment among sharing users, which was especially pronounced among GMO opponents. Building on these findings, the ERGM further demonstrated that both endogenous network mechanisms (reciprocity, preferential attachment, and triadic closure) and positional homophily influence GMO risk information sharing and dissemination. A key finding is the presence of a differential homophily effect in which GMO opponents exhibit stronger homophilic tendencies than non-opponents. Despite the prevalence of homophily, this chapter uncovers substantial cross-attitudinal interactions, challenging simplistic notions of echo chambers in GMO risk communication.