The Rorschach Interaction Scale as a potential predictor of cancer.

&NA; In a long‐term prospective study, medical students who later developed cancer, in contrast to the rest of the cohort, gave Rorschach test responses indicating less satisfactory interpersonal relationships as assessed by the Rorschach Interaction Scale (RIS). The scale remained as a predictor of cancer after adjusting for smoking, serum cholesterol level, and age in medical school, and after taking into account the date of diagnosis and length of follow‐up time. An exploration of the relationship between the RIS and specific types of cancer suggested that cancers of the lung may be less influenced by this psychologic factor than are other cancers. The findings were interpreted to suggest that internal self‐other representations as measured by the RIS are involved as regulators of biologic systems and manifestations of illness, such as cancer.