The impact of self-affirmation on defensive processing of health messages: A meta-analysis

Abstract

This meta-analysis studies the effects of self-affirmation on cognitive, affective, and behavioral responses to threatening health messages. It analyzes how the effects vary as a function of three moderators: self-affirmation domains, health topics, and self-relevance levels. In addition, this analysis examines the role of emotions in the self-affirmation process. Effect sizes for 11 outcome variables were extracted from 55 studies and analyzed (N = 10,611). I performed fixed-effect and random-effects models to examine the main effect and moderating effects. Both models indicated small but statistically significant positive effects of self-affirmation in increased perceived message effectiveness, perceived susceptibility, response efficacy, and behavior. The results lend empirical support to self-affirmation as an effective intervention strategy. Moderator analyses with both fixed-effect and random-effects models revealed that self-affirmation was most effective (1) when we used the desirable traits self-affirmation domain; (2) when we exposed participants to messages of unhealthy behaviors cessation; and (3) among participants with low self-relevance. The two most commonly used self-affirmation domains (i.e., desirable traits and values), did not work equally well in reducing defensiveness. Moreover, these two domains were not effective in restoring self-integrity when applied to high-self-relevance populations, or to reducing defensive responses to messages of unhealthy behavior cessation. Meta-analytic review of the role that emotions play in the self-affirmation process shows that self-affirmation was effective in reducing negative emotions aroused by delivery of threatening health messages. However, the evidence of a mediating role of (positive) emotions in the self-affirmation process is scant.