People usually know what they are doing, intend to do, or have done in the past. How people achieve an unambiguous understanding of their behavior is rather remarkable when one considers the variety of ways in which any action can be identified. “Taking a test,” for example, could be identified as “showing one's knowledge,” “earning a grade,” or “answering questions.” Action identification theory, developed by Robin Vallacher and Daniel Wegner, specifies the principles by which people adopt a single act identity for their behavior and outlines the conditions under which people maintain this act identity or adopt a new one. The interplay of these principles has implications for central issues in social psychology, including self-regulation, vulnerability to social influence, and self-concept.

The potential ...