A Principal Components Analysis of Rorschach Aggression and Hostility Variables

Abstract

We examined the structure of 9 Rorschach variables related to hostility and aggression (Aggressive Movement, Morbid, Primary Process Aggression, Secondary Process Aggression, Aggressive Content, Aggressive Past, Strong Hostility, Lesser Hostility) in a sample of medical students (N= 225) from the Johns Hopkins Precursors Study (The Johns Hopkins University, 1999). Principal components analysis revealed 2 dimensions accounting for 58% of the total variance. These dimensions extended previous findings for a 2-component model of Rorschach aggressive imagery that had been identified using just 5 or 6 marker variables (Baity & Hilsenroth, 1999; Liebman, Porcerelli, & Abell, 2005). In light of this evidence, we draw an empirical link between the historical research literature and current studies of Rorschach aggression and hostility that helps organize their findings. We also offer suggestions for condensing the array of aggression-related measures to simplify Rorschach aggression scoring.

Acknowledgments

We thank Michael Klag and Lucy Meoni for providing us with Rorschach protocols collected as part of the Johns Hopkins University Precursors Study.

Editor's Note. Mark Blais served as Editor for this manuscript with full decision authority.

Nicholas J. Katko is now at The Menninger Clinic Houston, Texas. George Bombel is now at The Austin Riggs Center, Stockbridge, Massachusetts.

Notes

¹Tetrachoric correlations could have been used for the principal components analysis. However, tetrachoric correlations statistically adjust the distributions of low frequency variables to achieve increased normality; but in doing so, overlook how those variables (e.g., A1, AgPot) are expected to occur rarely. In our view, tetrachoric correlations are appropriate in cases in which skewed frequency distributions reflect an atypical or anomalous base rate rather than an intrinsic feature of the data. Also using Pearson correlations allowed for a more direct comparison of our findings with those from past studies.