An evaluation of a differential classification system for young offenders : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology at Massey University
The aim of the present study was to examine the application and utility of the Quay and Parsons (1971) differential classification system for the classification of young offenders, in a New Zealand sample. It was also proposed to examine the construct validity of this system, by relating its subcategories to various psychological dimensions. Sixty-five consecutive new admissions to the Manawatu Youth Institution were administered the Quay and Parsons (1971) classification system. Each subject also completed the Standard Progressive Matrices, the Peabody Picture Vocabulary Test-Revised, the Neuroticism Scale Questionnaire, the Machiavellianism Scale, a Role-taking task and the Rosenzweig Picture Frustration Study. Results on the above measures were mixed, with research based expectations being confirmed on some dimensions but not on others. Overall there were greater similarities between the three young offender subcategories, than there were differences between them. There was no strong support, therefore, for the construct validity of this system for a New Zealand sample. Social, cognitive and psychological characteristics of the sample as a whole were identified, however, and the relevance of these to possible treatment changes are discussed. On the basis of this study the incorporation of the Quay and Parsons (1971) system into existing classification procedures is not recommended without further refinement and research being conducted with it.