DATA FROM FILES CONTAINING RESULTS OF INDIVIDUALLY ADMINISTERED INTERPERSONAL MATURITY (I-LEVEL) DIAGNOSES AND PSYCHOLOGICAL EVALUATIONS FOR BLACK AND WHITE OFFENDERS FORMED THE BASIS FOR THIS STUDY. MEAN AGE WAS 17.5 YEARS, AND ALL WERE 'SERIOUS' OFFENDERS WHO HAD BEEN PLACED ON PROBATION IN LIEU OF INCARCERATION UNDER CALIFORNIA'S EXPERIMENTAL SUBSIDY PROBATION PROGRAM. STRONG INTERACTIONS WERE FOUND AMONG AGE, I-LEVEL, VERBAL INTELLIGENCE QUOTIENT (IQ), AND ETHNICITY. FOR MALES, A STRONG CORRELATION WAS APPARENT BETWEEN I-LEVEL AND VERBAL IQ, ESPECIALY FOR ANGLOS. ANGLOS DEMONSTRATED HIGHER I-LEVELS THAN BLACKS, AND FEMALES HAD HIGHER I-LEVELS THAN MALES. HOWEVER, AGE HAD A CONFOUNDING EFFECT FOR BOTH MALES AND FEMALES, WITH THE GREATER EFFECT SEEN FOR MALES. THE OLDER THE PERSON, THE HIGHER THE I-LEVEL REGARDLESS OF VERBAL IQ. FUTURE WORK ON I-LEVEL THEORY SHOULD CONTROL FOR SEVERAL VARIABLES: SEX, ETHNICITY, VERBAL IQ, AND AGE. SINCE AGE AND VERBAL IQ SHOW SUCH A STRONG RELATIONSHIP, RESEARCHERS SHOULD ASK WHY LOWER VERBAL IQ IS CHARACTERISTIC OF YOUNGER VERSUS OLDER OFFENDERS. TABLES PRESENTING STUDY DATA, NOTES, AND 30 REFERENCES ARE INCLUDED.