Interacting as equals reduces partisan polarization in Mexico

In many contemporary democracies, political polarization increasingly involves deep-seated intolerance of opposing partisans. The decades-old contact hypothesis suggests that cross-partisan interactions might reduce intolerance if individuals interact with equal social status. Here we test this idea by implementing collaborative contact between 1,227 pairs of citizens (2,454 individuals) with opposing partisan sympathies in Mexico, using the online medium to credibly randomize participants' relative social status within the interaction. Interacting under both equal and unequal status enhanced tolerant behaviour immediately after contact; however, 3 weeks later, only the salutary effects of equal contact endured. These results demonstrate that a simple, scalable intervention that puts people on equal footing can reduce partisan polarization and make online contact into a prosocial force.