The Operationalization of Self-Identity in Reasoned Action Models: A Systematic Review of Self-Identity Operationalizations in Three Decades of Research

Self-identity has frequently been proposed as a useful addition to the Theory of Planned Behavior; yet Fishbein and Ajzen decided to not include self-identity when they published that theory’s successor, the Reasoned Action Approach. One of their reasons for exclusion is the lack of clear conceptual independence, as manifested in self-identity operationalizations that often conflate the construct with attitudinal or normative measures. Therefore, establishing whether self-identity has added value in the Reasoned Action Approach first requires synthesis of the used operationalisations to develop an operationalization that captures self-identity but not attitude and perceived norm. In this systematic review, 342 of the operationalisations of self-identity were identified in studies operationalising it as a potential Reasoned Action Approach extension. After analysing the full item pool to eliminate duplicates and items that did not measure self-identity or measured attitudes or norms, did not allow tailoring formulations to target, action, context and time, were not applicable to a wide variety of behaviors, or were ambiguous, seven prototypical items remained. These items lend themselves well for further psychometric study to establish the conceptual independence of self-identity from other Reasoned Action Approach constructs such as attitude and perceived norms.