AVAILABLE DATA ARE SAID TO SUPPORT THE ASSERTION THAT IQ AFFECTS THE LIKELIHOOD OF DELINQUENT BEHAVIOR THROUGH ITS EFFECT ON SCHOOL PERFORMANCE. RESEARCH DATA SUGGEST THAT THE RELATIONSHIP BETWEEN INTELLIGENCE AND DELINQUENCY IS AT LEAST AS STRONG AS THAT BETWEEN OFFICIAL DELINQUENCY AND EITHER CLASS OR RACE, AND STRONGER THAN THAT BETWEEN SELF-REPORTED DELINQUENCY AND EITHER CLASS OR RACE. THE VIEW THAT IQ IS NOT AN IMPORTANT FACTOR IN DELINQUENCY IS ATTRIBUTED TO THE FOLLOWING DEVELOPMENTS: THE SHIFT IN EMPHASIS FROM MEDICAL TO SOCIOLOGICAL PATTERNS; THE FAILURE OF RESEARCH TO DEAL WITH EARLY, EXORBITANT CLAIMS THAT LOW IQ ALONE EXPLAINS ILLEGAL BEHAVIOR; EARLY NEGATIVE REVIEWS OF RESEARCH ON THE SUBJECT; RESERVATIONS ABOUT THE VALIDITY OF METHODS OF MEASURING IQ AND DELINQUENCY; MISINTERPRETATION OF RESEARCH FINDINGS; AND SPECULATION ABOUT FACTORS THAT MIGHT ACCOUNT FOR THE IQ-DELINQUENCY RELATIONSHIP. IT IS POINTED OUT THAT MANY PROMINENT SOCIOLOGICAL THEORIES OF DELINQUENCY IMPLICITLY OR EXPLICITLY USE IQ AS A CRUCIAL ELEMENT. THREE TABLES AND A LIST OF REFERENCES ARE INCLUDED. (AUTHOR ABSTRACT MODIFIED).