Rationality, Identity, and Expression.

Psychological identification with a group is often posited as a fundamental motivation in politics. Identity then serves a motivating force, in that it demands solidarity with a group, determines expectations or interpretations of the actions of others, and dictates adherence to principles. This survey attemps to clarify both the differences and complementarities by examining rational-choice contributions to two areas in political science: (1) voting, party, and ideology; and (2) ethnic politics and ethnic conflict.