Social identity is believed to play an important role in the continuation of conflict between groups. McBride and co-authors constructed a game-theoretic model of inter-group conflict that accounts for social identity, and found that conflict is non-monotonic in identity. When actors have weak identity, conflict begins but quickly dies out; with medium identity, conflict begins and continues; with high identity the fear of retaliation deters conflict from starting. They tested these predictions in a laboratory experiment that varies the strength of group identity. Preliminary findings show that conflict originates at the same rate in all conditions, but that conflict is more likely to continue as identity is more salient.