Local majority-with-inertia rule can explain global consensus dynamics in a network coordination game

We study how groups reach consensus by varying communication network structure and individual incentives. In 342 networks of seven individuals, single opinionated “leaders” can drive decision outcomes, but do not accelerate consensus formation, whereas conflicting opinions slow consensus. While networks with more links reach consensus faster, this advantage disappears under conflict. Unopinionated individuals make choices consistent with a local majority rule combined with “inertia” favouring their previous choice, while opinionated individuals favour their preferred option but yield under high peer or time pressure. Simulations show these individual rules can account for group patterns, and allow rapid consensus while preventing deadlocks.