The validity of individual Rorschach variables: systematic reviews and meta-analyses of the comprehensive system

We systematically evaluated the peer-reviewed Rorschach validity literature for the 65 main variables in the popular Comprehensive System (CS). Across 53 meta-analyses examining variables against externally assessed criteria (e.g., observer ratings, psychiatric diagnosis), the mean validity was r = .27 (k = 770) as compared to r = .08 (k = 386) across 42 meta-analyses examining variables against introspectively assessed criteria (e.g., self-report). Using Hemphill's (2003) data-driven guidelines for interpreting the magnitude of assessment effect sizes with only externally assessed criteria, we found 13 variables had excellent support (r ≥ .33, p < .001; [Symbol: see text] FSN > 50), 17 had good support (r ≥ .21, p < .05, FSN ≥ 10), 10 had modest support (p < .05 and either r ≥ .21, FSN < 10, or r = .15-.20, FSN ≥ 10), 13 had little (p < .05 and either r = < .15 or FSN < 10) or no support (p > .05), and 12 had no construct-relevant validity studies. The variables with the strongest support were largely those that assess cognitive and perceptual processes (e.g., Perceptual-Thinking Index, Synthesized Response); those with the least support tended to be very rare (e.g., Color Projection) or some of the more recently developed scales (e.g., Egocentricity Index, Isolation Index). Our findings are less positive, more nuanced, and more inclusive than those reported in the CS test manual. We discuss study limitations and the implications for research and clinical practice, including the importance of using different methods in order to improve our understanding of people.