HERETOFORE, STUDIES OF DELINQUENTS AND NONDELINQUENTS HAVE FAILED TO CONTROL FOR INSTITUTIONALIZATION. TO REMEDY THIS, 168 YOUNG MALE ORIENTAL JEWS OF LOW SOCIOECONOMIC AND EDUCATIONAL LEVELS WERE INTERVIEWED BY TRAINED RESEARCHERS. THEY INCLUDED 82 INSTITUTIONALIZED NONDELINQUENTS (SOLDIERS SERVING 3-YEAR TERMS IN THE ISRAELI ARMY), 16 DELINQUENTS ON PROBATION, AND 22 VOCATIONAL SCHOOL STUDENTS. IT WAS FOUND THAT BOTH INSTITUTIONALIZED GROUPS WERE MORE PREOCCUPIED WITH EVENTS WITHIN THE INSTITUTION, BUT ONLY AMONG PRISONERS DID THIS DIFFERENCE REACH SIGNIFICANCE. BOTH NONINSTITUTIONALIZED GROUPS WERE MORE INVOLVED WITH FUTURE PLANS, JOBS, AND OTHER COGNITIVE-INSTRUMENTAL ISSUES. HOWEVER, AMONG BOTH PRISONERS AND SOLDIERS, THE CLOSER THE TIME CAME FOR RELEASE, THE MORE THEY CONSIDERED COGNITIVE-INSTRUMENTAL MATTERS. INSTITUTIONALIZED DELINQUENTS WERE MORE CONCERNED WITH DEVIANT AND DELINQUENT MATTERS THAN EITHER THE SOLDIERS OR THE NONINSTITUTIONALIZED DELINQUENTS. THESE FINDINGS ARE RELATED TO OTHER STUDIES WHICH PUT FORTH THE CONCEPT OF 'PRISONIZATION.' IT IS HYPOTHESIZED THAT THE MIDDLE OF A PRISON TERM IS A VULNERABLE PERIOD WHEN THE INSTITUTIONALIZED PERSON HAS NO PEER GROUP OTHER THAN FELLOW INMATES. A MODEL INCORPORATING SEVERAL ASPECTS OF THE 'PRISONIZATION' PROCESS IS DEVELOPED. TABLES AND CHARTS ILLUSTRATE THE STUDY DATA. REFERENCES ARE PROVIDED. (GLR)