A sample of child guidance clinic cases with a young adult onset of schizophrenia were followed into middle age. Outcome ratings and marital status were used as predictive criteria for childhood measures of IQ, aggressiveness, and severity of disturbance. The interaction of IQ and levels of aggressive symptomatology revealed a subgroup of preschizophrenics with low IQ and below average aggressiveness who had disproportionately unfavorable adult outcomes and never-married status. The results demonstrated the important moderating effects of a second variable on the predictive statements made about an initial predictor.