Attitudes serve multiple functions, some related to the self-concept. We call attitudes that help people define who they are "self-defining." Across four studies, we tested a brief self-report measure of the extent to which an attitude is self-defining. Studies 1 and 2 showed that self-defining attitudes tend to be extreme, positive, and unambivalent. Studies 3 and 4 produced two main findings. First, self-definition was related to, but not redundant with, a number of other characteristics of the attitude (e.g., attitude certainty). Second, self-definition predicted participants' intentions to spontaneously advocate and, in Study 4, their reactions to an opportunity to advocate behaviorally (i.e., writing about their attitude in an optional response box) following a self-threat. Overall, the results highlight the utility of this approach and, more broadly, demonstrate the value of considering the role of the self in attitudinal processes, and vice versa.
Keywords: advocacy; attitude functions; attitudes; identity; self-concept.