NORMAL PERSONALITY-CHARACTERISTICS IN IDENTICAL-TWINS DISCORDANT FOR SCHIZOPHRENIA

The authors examined normal personality characteristics of monozygotic (MZ) twins discordant for schizophrenia. Twenty pairs of discordant t wins were analyzed; 11 pairs of MZ twins concordant for schizophrenia served as a comparison group. Personality was assessed using the Multi dimensional Personality Questionnaire (MPQ; A. Tellegen, 1995). Among discordant twin pairs, twins with schizophrenia were more deviant than normal co-twins on all but 4 of the MPQ's scales. Analysis of MZ tain correlations among the discordant twin pair; revealed substantial ero sion of personality similarity as compared to normal individuals, alth ough a cluster of scales related to Constraint/ Psychoticism showed si gnificant correlations. The results highlight striking personality div ergence related to nonshared environmental influences. It is not possi ble to determine the point at which the twins diverged, although previ ous findings from this sample suggest that the observed personality di fferences may reflect effects of schizophrenia on normal personality.