cattell and his co-workers also constructed downward extensions of the 16pf – parallel personality questionnaires designed to measure corresponding trait constructs in younger age ranges, such as the high school personality questionnaire (hspq) – now the adolescent personality questionnaire (apq) for ages 12 to 18 years, the children's personality questionnaire (cpq), the early school personality questionnaire (espq), as well as the preschool personality questionnaire (pspq).