THE PRINCIPAL INVESTIGATION WAS CARRIED OUT IN 13 INSTITUTIONS REPRESENTING AS FAR AS POSSIBLE MALE AND FEMALE INSTITUTIONS OF EVERY TYPE. THE TARGET GROUP FOR THE SURVEYS WAS ALL INMATES IN THE INSTITUTION. RESPONSE RATES FOR THE FIRST AND SECOND SURVEYS WERE 92 PERCENT AND 96 PERCENT RESPECTIVELY. RESULTS WERE OBTAINED ON THE FOLLOWING FACTORS: THE INFORMAL SOCIAL SYSTEM, THE IMPACT OF IMPRISONMENT, NEGATIVE EFFECTS OF INSTITUTIONALIZATION, POSITIVE EFFECTS, POLITICAL ATTITUDES OF PRISONERS, SOCIALIZATION IN PRISONS, AND THE INMATE SUBCULTURE. THE AUTHOR CONCLUDES THAT INSTITUTIONAL TREATMENT FAILS NOT ONLY TO FULFILL ITS OFFICIAL THERAPEUTIC FUNCTION BUT EVEN MILITATES AGAINST REHABILITATION....DMC