As a complement to the familiar idea of self-conception, the concept of role-person merger is proposed as a more behavioral approach to understanding the social construction of personality than has been taken previously. Person and role are said to be merged when there is a systematic pattern involving failure of role compartmentalization, resistance to abandoning a role in the face of advantageous alternative roles, and the acquisition of role-appropriate attitudes. Three principles concerning appearance, effect, and consistency provide the basis for a series of propositions concerning interactive determinants of merger. Three other principles-consensual frames of reference, autonomy and favorable evaluation, and investment- provide the basis for propositions concerning individual determinants of role-person merger.