A thirty-year follow-up of treatment effects

Over 500 men, half of whom had been randomly assigned to a treatment program to prevent delinquency (E. Powers and H. Witmer, 1951) that lasted approximately 5 yrs (1939-1944), were traced 30 yrs after termination of the project. Although subjective evaluations of the program by those who received its benefits would suggest that the intervention had been helpful, comparisons between the treatment and control groups indicate that the program had negative side effects as measured by criminal behavior, death, disease, occupational status, and job satisfaction. Several possible processes are suggested in explanation of these findings.