Common Physical Properties Improve Metaphor Effect Even in the Context of Multiple Examples

Abstract

A previous experimental analog study by Sierra et al. International Journal of Psychology and Psychological Therapy, 16, 265–279 (2016) showed that including common physical properties of participants’ pain in the metaphor content improved its effect in promoting pain tolerance. Using a 2x2 factorial design, this study analyzed the effect of common physical properties in the context of multiple examples of functionally equivalent metaphors. Eighty-four participants responded to a measure of experiential avoidance. They were subsequently exposed to a cold-pressor task at pretest. Participants were then randomly assigned to four experimental protocols: (a) three functionally equivalent metaphors with common physical properties of participants’ pain, (b) three functionally equivalent metaphors without common physical properties, (c) a metaphor with common physical properties that was repeated three times, and (d) a metaphor without common physical properties that was repeated three times. Participants were then reexposed to the cold-pressor task (posttest). Bayesian data analyses showed that the presence of common physical properties was the only variable associated with an increase of the metaphor effect, and this was independent of the number of metaphors proposed. The update of evidence by means of a Bayes factor meta-analysis showed that data very strongly support the hypothesis of common physical properties being an effective component of metaphors. These results highlight the relevance of training therapists in designing metaphors with common physical properties of the clients’ discomfort.