A corollary to this thesis is proposed: intervention prior to school entry that improves academic potential and school performance for a sample at high risk for school failure will reduce the likelihood of delinquency in that sample. Findings from multiple regression analysis indicate that school success exerts a substantial impact on one type of delinquency and a moderate effect on the other three types of delinquency, but its effect does not occur through its impact on IQ or scholastic achievement. Attachment to school affects three of the outcomes but does so in a way that is independent of IQ or achievement scores. Data tables and 35 references. (Author abstract modified)