Seven judges described the personality characteristics of the primary psychopath by sorting the 100 items of the California Q-set in a forced-normal distribution. Item scores resulting from these sorts were aggregated across judges to form a Psychopathy Prototype. The reliability of the seven-judge aggregate prototype was .90. To examine the reliability of scores derived from the prototype, the personalities of 65 target subjects were described by two peer judges using the California Q-set (Block, 1961). For each subject, Psychopathy Prototype scores were derived by correlating each judge's Q-sort profile with the Psychopathy prototype. Findings indicated that the peer-generated psychopathy scores correlated r = .61 between judges. Using the Spearman-Brown formula, Psychopathy Prototype scores have reliabilities of .75, .82, and .86 when aggregated over two, three, and four peer judges, respectively. To further explore properties of the measure, the Psychopathy Prototype was compared with independently developed California Q-set prototypes describing the narcissist and the female hysteric. The results revealed some interesting contrasts among these concepts and serve to support our contention that the Psychopathy Prototype has utility in regard to distinguishing between pathologies with overlapping features.