Several MECHANISMS papers use mediation analysis and/or network-analytics to test hypothesised chains: e.g., intervention → change in normative beliefs → friend-group norm shift → change in behaviour/intent. These underscore that shifts in perceived peer norms and peer behaviour modelling are often the intermediate steps between intervention and outcome. They also highlight that network structure (e.g., density of ties, clustering, centrality of change-agents) moderates the strength of those mediation pathways.