Formal operational ability and interpersonal understanding, possible predictors of adolescent egocentrism, were studied in 87 adolescents from 4 age groups--preadolescents, ages 11-12; young adolescents, ages 13-14; adolescents, ages 16-17; young adults, ages 18-21. Interpersonal understanding level did predict egocentrism as measured by a subscale of Adolescent Egocentrism-Sociocentrism Scale, but formal operations did not predict any form of adolescent egocentrism. (SLD)