Meta-Analysis of the Persuasive Effects of Metaphorical vs. Literal Messages

Abstract

This study uses meta-analysis to compare the persuasive effects of metaphorical and literal messages and assess various theoretical explanations for the relatively greater persuasiveness of metaphor. The meta-analysis includes studies from 2001 to 2015 that use various message formats and topics. Results indicate an overall effect size of r = 0.09, p < .001, 95% CI [0.06, 0.12], which supports the conclusion that metaphorical messages are more persuasive than literal messages. Moderator analyses indicate differences in effect sizes based on metaphor target familiarity, message topic, and message format. A meta-regression using the theoretical moderators indicates that message format was the strongest predictor of variation in effect size. This study provides implications related to the theoretical mechanism behind the greater persuasive effects of metaphor.