FROM 1950 TO 1966, 139 BOYS AGED 14 TO 18 WERE HOUSED AT THIS REEDUCATION HOME FOR DELINQUENT AND EMOTIONALLY DISTURBED YOUTH, WITH ABOUT 20 LIVING THERE AT A TIME. ONE DIED ACCIDENTALLY SHORTLY AFTER LEAVING, 30 WHOSE STAY WAS SHORTER THAN 6 MONTHS WERE STUDIED SEPARATELY, AND THE BALANCE OF 108, AGED 21 TO 36 IN 1974, PROVIDE THE PRIMARY FOCUS OF THIS STUDY. INFORMATION ON THEIR CHILDHOOD WAS OBTAINED FROM FILES OF THE REFERRING SOCIAL AGENCIES AND OF THE HALFWAY HOUSE ITSELF. LATER, INFORMATION WAS OBTAINED FROM POLICE AND OTHER OFFICIAL RECORDS, FROM A QUESTIONNAIRE TO WHICH ABOUT 20 RESPONDED, AND FROM INTERVIEWS WITH 58 OF THE SUBJECTS. PREENTRY DATA REFERRED TO 23 FACTORS SUCH AS SOCIAL CLASS, FAMILY LIFE, INTELLIGENCE, EMPLOYMENT STATUS, AND CRIMINAL HISTORY. ONLY 16 PERCENT HAD COME FROM TWO-PARENT HOMES, WITH 67 PERCENT HAVING BEEN RAISED BY ONE PARENT, AND THE REST HAVING BEEN EITHER ORPHANED OR ABANDONED BY BOTH PARENTS. ONLY 14 PERCENT OF THE BOYS HAD PREVIOUS CRIMINAL RECORDS. IN ADDITION, FOUR KINDS OF EMOTIONAL PROBLEMS WERE IDENTIFIED: ANTISOCIAL BEHAVIOR, TEMPERAMENTAL PROBLEMS, NERVOUS DISORDERS, AND CASES OF PREPSYCHOTIC OR BORDERLINE BEHAVIOR. EMOTIONAL PROBLEMS OF VARYING SEVERITY WERE EXPERIENCED BY 92 PERCENT OF THE YOUTH, BUT NO TRUE PSYCHOTICS WERE PLACED AT VITRY. SUBJECTS HAVING THE LONGEST SEPARATION FROM THEIR PARENTS BEFORE ENTERING WERE MUCH MORE LIKELY TO EXHIBIT ANTISOCIAL BEHAVIOR AFTER LEAVING. THE AVERAGE STAY WAS 864 DAYS. SUCCESSFUL PARTICIPATION IN THERAPY WAS LINKED TO PREENTRY FACTORS AND CORRELATED WITH SUCCESSFUL ADAPTATION IN ADULT LIFE. OF THE GROUP OF 108 FORMER INMATES, 86 EXHIBITED NO CRIMINAL BEHAVIOR AFTER RELEASE, AND THE 22 WHO DID HAD ALL COMMITTED CRIMES BEFORE ENTRY. THE RECORD WAS LESS FAVORABLE FOR THE GROUP OF 30 WHO WERE STUDIED SEPARATELY BECAUSE THEY HAD STAYED LESS THAN 6 MONTHS; OF THESE, 8 HAD SUBSEQUENT CRIMINAL RECORDS. IT WAS ASCERTAINED THAT THE LONGER THE STAY AT VITRY, THE BETTER THE PROGNOSIS FOR A CRIME-FREE FUTURE. FURTHER FINDINGS SHOWED THAT NO INMATE WAS 'CONTAMINATED' BY DELINQUENT COMRADES AND THE PERCENTAGE OF FORMER JUVENILE DELINQUENTS REMAINING ANTISOCIAL IN ADULT LIFE WAS LESS THAN FOR THE GENERAL POPULATION (EXCEPT IN THE CASE OF THE GROUP OF 30). TABLES, FOOTNOTES, A BIBLIOGRAPHY, AND A LIST OF FILMS ON THE VITRY HOME ARE INCLUDED. --IN FRENCH. (MRS)