Self-identity and the theory of planned behaviour: Between- and within-participants analyses

Authors

  • Martin S. Hagger,

    Corresponding author
    1. University of Nottingham, UK
      Correspondence should be addressed to Dr Martin S. Hagger, Risk Analysis, Social Processes, and Health Group, School of Psychology, Unversity of Nottingham, University Park, Nottingham NG7 2RD (e-mail: martin.hagger@nothingham.ac.uk).
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  • Nikos L. D. Chatzisarantis

    1. University of Plymouth, UK
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Correspondence should be addressed to Dr Martin S. Hagger, Risk Analysis, Social Processes, and Health Group, School of Psychology, Unversity of Nottingham, University Park, Nottingham NG7 2RD (e-mail: martin.hagger@nothingham.ac.uk).

Abstract

Two studies addressed the hypothesis that a minority of people are more oriented towards their self-identity when forming intentions to act than the traditional antecedents of intentional action; attitudes, subjective norms and perceived behavioural control (PBC). In Study 1, participants (N =241) completed measures of an augmented version of theory of planned behaviour (TPB) that included self-identity for 30 behaviours. Using within-participants multiple regression analyses, the sample was classified into self-identity-oriented (SI-oriented) and TPB-oriented groups. Between-participants multiple regression analyses revealed that self-identity was a significantly stronger predictor of intentions and accounted for significantly more incremental variance in intentions in the SI-oriented sample compared with the TPB-oriented sample across the 30 behaviours. In Study 2, participants (N =250) completed the same TPB and self-identity measures used in Study 1 as well as measures of generalized self-concept and social physique anxiety for dieting behaviour. Results indicated that self-identity was significantly associated with the generalized self-related measures, and self-concept and social physique anxiety moderated the self-identity-intention relationship. This investigation provides some preliminary evidence to support the effect of individual differences in self-identity on the formation of intentions to act.

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