Predictors of intentions to perform six cancer-related behaviours: roles for injunctive and descriptive norms.

This study reports an application of the integrative model to the prediction of intentions to engage in three cancer screening behaviours (mammogram, colonoscopy and PSA test) and three healthy lifestyle behaviours (exercising, eating fruits and vegetables, and controlling ones diet to lose weight). We examined the roles of attitudes, perceived behavioural control, injunctive norms (what important others think one should do), and descriptive norms (perceptions of what others do) as predictors of participant's intentions to engage in each behaviour. Results indicated that injunctive norms were the strongest predictors of prostate and colon cancer screening intentions and contributed significantly to the prediction of intentions to get a mammogram. In contrast, injunctive norms contributed relatively little to the prediction of lifestyle behaviours, but were strongly predictive of intentions to eat fruits and vegetables. Implications for designing behaviour-specific communications and interventions are discussed.