MORE ACCURATE TESTS OF SOCIAL CLASS DELINQUENCY THEORIES CAN BE MADE IF THE FATHER'S SOCIOECONOMIC STATUS (SES) AS JUDGED BY HIS OCCUPATION IS REPLACED BY A MORE ACCURATE MEASURE OF SES. THE UNDERCLASS (UC) CONCEPT MEASURES CRITERIA SUCH AS MARGINAL EMPLOYMENT OR UNEMPLOYMENT, POVERTY LEVEL INCOME, AND RECEIPT OF WELFARE BENEFITS; EARNING CLASS (EC) STATUS LABELS THOSE WHO DO NOT FIT IN THE UC CATEGORY. THIS STUDY EXAMINED ANONYMOUS QUESTIONNAIRES OBTAINED FROM 734 HIGH SCHOOL SOPHOMORES IN 3 SAMPLE HIGH SCHOOLS. ALTHOUGH THE SCHOOLS WERE SELECTED IN ORDER TO OBTAIN A SUFFICIENT NUMBER OF UC STUDENTS, ONLY 8 PERCENT WERE EVENTUALLY CLASSIFIED AS UC. IN ADDITION TO TESTING FOR UC/EC FACTORS A TRADITIONAL GAUGE OF THE FATHER'S OCCUPATION WAS OBTAINED IN ORDER TO DETERMINE IF ANY CLASS EFFECT FOUND WITH UC/EC MEASURE COULD BE ATTRIBUTED TO USING DIFFERENT MEASURES. THE DEPENDENT VARIABLE, SELF-REPORTED DELINQUENT BEHAVIOR, INCLUDED CHARGEABLE OFFENSES SUCH AS THEFT, VANDALISM AND ASSAULT. THE DATA PROVIDED NO FIRM EVIDENCE THAT SOCIAL CLASS, NO MATTER HOW IT IS MEASURED, IS A SALIENT FACTOR IN GENERATING DELINQUENT INVOLVEMENT. UC/EC WAS ONLY SLIGHTLY MORE RELATED TO SERIOUSNESS OF DELINQUENT BEHAVIOR. CORRELATIONS BETWEEN SES OF FATHER'S OCCUPATION AND THOSE SAME MEASURES OF DELINQUENCY WERE NON-EXISTENT. ALTHOUGH FURTHER TESTS ENCOMPASSING SLUM AREAS WITH LARGER UC POPULATIONS ARE NEEDED TO MORE FULLY TEST THE UC/EC MODE, THERE IS ONLY A MODERATE IMPLICATION THAT IMPROVED METHODOLOGY WILL REVEAL THAT THE EXPERIENCE OF BEING A MEMBER OF THE UC LEADS TO GREATER INVOLVEMENT IN CERTAIN ILLEGAL ACTIVITIES. REFERENCES ARE APPENDED.