An examination of the individual difference approach to the role of norms in the theory of reasoned action

The relationship between subjective norm and behavioral intentions is the weakest link of the Theory of Reasoned Action (TRA). Numerous approaches have been proposed to address this issue, including the assertion that the weak contribution is due to the inclusion of a small number of individuals who are under normative control in studies of the TRA (e.g., Trafimow & Finlay, 1996). The present research examines this individual difference approach in the domain of health behaviors. Respondents were 287 undergraduate students who rated their intentions, attitudes and subjective norms in relation to 32 health behaviors and five substance use behaviors. Regression analyses conducted between-subjects for each behavior and within-subjects across all of the behaviors demonstrated that there is support for the notion that both behaviors and people can be characterized as being under attitudinal or normative control. However, support for an individual difference approach was less conclusive when findings were examined separately for each behavior. In addition, the present study found limited support for the application of an individual difference approach to a subset of more specific health behaviors; substance use