The impact of changing attitudes, norms, and self-efficacy on health-related intentions and behavior: a meta-analysis

Abstract

Background: Health behavior theories converge on the hypothesis that attitudes, norms, and self-efficacy are important determinants of intentions and behavior. The present review analyzed whether changing attitudes, norms, or self-efficacy leads to changes in intentions and behavior in studies that used random assignment, manipulation checks, and post-intervention measures of outcomes. Methods: Literature searches obtained 193 experimental tests that met the inclusion criteria, which were meta-analyzed via STATA. Findings: Experimentally induced changes in attitudes, norms, and self-efficacy all led to medium-sized changes in intention (d+ = .50, .41, and .50, respectively), and engendered small to medium-sized changes in behavior (norms-d+ = .20; attitudes-d+ = .37; self-efficacy-d+ = .46). These effect sizes generally were not qualified by the moderator variables examined (e.g., study quality, methodological characteristics). Discussion: The present review (a) indicates that correlational studies (and related meta-analytic syntheses) overestimate the effect of cognitions on intentions and behavior, (b) lends novel, experimental support for key predictions from health behavior theories, and (c) demonstrates that interventions that modify attitudes, norms, and self-efficacy are effective in promoting health behavior change.