Political science, like other fields of social inquiry, has had an enduring interest in questions of stability and change. This interest—until now principally expressed in studies of the rise and fall of institutions—has lately been focused increasingly upon individual and group behavior, in a search for the influences that hold men to their political beliefs and affiliations or cause them to shift about. Such influences are important not only for the study of voting and party membership, but for haute politique as well—for the great and dramatic questions surrounding political loyalty, conformity, deviation, apostasy, and other states of membership or disaffiliation. Although the research reported below concentrates on the former, it is our hope that it may also cast light upon the latter. It is concerned specifically with primary groups—those small, face-to-face, solidary, informal and enduring coteries that we commonly experience as family, friendship and occupational peer groups.