The effect of self-identity alongside perceived importance within the theory of planned behaviour

Self-identity often predicts behavioural intentions after standard theory of planned behaviour (TPB) components are accounted for. However, it has been claimed this is due to conceptual similarity between self-identity and perceived importance of the behaviour. We examined this claim within the context of recycling food waste. Participants (N=113) completed questionnaires assessing intentions, attitude, perceived behavioural control, perceived norms, perceived importance, self-identity, and past behaviour. Confirmatory factor analysis indicated that self-identity and perceived importance were distinct constructs. Further, after accounting for TPB components and perceived importance, self-identity explained a significant amount of additional variance in intentions. The present findings therefore do not support this particular argument against the predictive utility of self-identity.