How to Test Questions About Similarity in Personality and Social Psychology Research

Social and personality psychologists are often interested in the extent to which similarity, agreement, or matching matters. The current article describes response surface analysis (RSA), an approach designed to answer questions about how (mis)matching predictors relate to outcomes while avoiding many of the statistical limitations of alternative, often-used approaches. We explain how RSA provides compressive and often more valid answers to questions about (mis)matching predictors than traditional approaches provide, outline steps on how to use RSA (including modifiable syntax), and demonstrate how to interpret RSA output with an example. To bolster our argument that RSA overcomes many limitations of traditional approaches (i.e., incomplete or misleading inferences), we compare results from four popular approaches (i.e., difference scores, residuals, moderated regression, and the truth and bias model) to those obtained from RSA. We discuss specific applications of RSA to social and personality psychology research.