Entrepreneurs of sustainable identity in groups that value similarity or diversity: trajectories of change

This paper proposes that environmental pioneers can drive norm change by adopting an ideological minority position that accentuates the group's distinct sustainable identity. We studied 107 Dutch-speaking participants in three online group discussions with a vegan confederate, using a longitudinal design with 4 timepoints. Contrary to prior work suggesting that vegans evoke resistance, our findings demonstrate shifts towards veg*nism in participants' attitudes, behaviors, and biospheric values. Two change trajectories emerged depending on (experimentally manipulated) group value orientation: diversity-valuing groups demonstrated a gradual norm shift through elaboration on the vegan perspective, while similarity-valuing groups shifted faster to a prototypical vegan pioneer. Group dynamics revealed that consensualisation predicted norm perceptions across conditions, while conformity pressure mattered only in similarity-valuing groups.