– Author reports a randomized controlled trial that assigns repeated intergroup contact between members of different ethnic groups. The contact results in exclusionary attitudes toward the outgroup.
– This experiment demonstrates that even very minor demographic
change causes strong exclusionary reactions.
– Exclusionary attitudes can be stimulated by even very minor, noninvasive demographic change: in this case, the introduction of only two persons. Overtly threatening behavior by newcomers is not a necessary component for the stimulation of exclusionary attitudes.
– Developed nations and politically liberal subnational units are expected to experience a politically conservative shift as international migration brings increased intergroup contact.