During a period of ten months the authors of this book, each eminent in his respective field, had the unique opportunity of applying the psycho-analytic instrument to a group of legally recognized and adjudicated delinquents. The individuals selected for this undertaking had all been well known earlier, some of them, eight or more years previously, to the Judge Baker Guidance Centre, and had in their day undergone the customary clinical study and treatment available at this institution. In most cases, furthermore, the life of the offender had been fairly well known during the intervening years. But 'neither of the analysts at the time of the analysis was acquainted with the full material that had been obtained in the previous case study. For orientation, only a short review of the outstanding data was utilized, with no transcription of the offender's earlier statement of his own problems, attitudes or conflicts'.

This self-imposed limitation on the utilization of former records of the analysands was desirable because 'an essential part of the research project