Exploring Possible Ethnic Differences and Bias in the Rorschach Comprehensive System

Abstract

In this study I conducted a series of analyses to explore potential ethnic bias in Rorschach Comprehensive System variables using a consecutive series of 432 patients evaluated in 1 setting. The simple association between 188 scores and ethnicity revealed no significant findings after matching on several salient demographic variables. Next, 17 analyses of convergent validity found no evidence for differential validity and no evidence for slope bias. For 13 analyses, there was also no evidence for intercept bias. However, with 4 variables predicting psychotic disorders, regression lines favored minorities and worked against European Americans. These findings are the opposite of what should be seen if the Rorschach was biased against minorities and most likely emerged for statistical reasons related to unmeasured confounds. Finally, principal components analyses revealed no evidence of ethnic bias in the Rorschach's internal structure. Although these findings need to be replicated, the available data support using the Comprehensive System across ethnic groups.