A threefold criterion is necessary for diagnosis of feeble-mindedness, namely, social incompetence, intellectual incompetence, and developmental arrest. "Idiocy, imbecility, and moronity are not mere successive stages of a mental age continuum, but are different categories of a common condition differing qualitatively as well as quantitatively from each other." Analysis of the above criteria of
... [Show full abstract] feeble-mindedness leads to the conclusion that some confusion now existing in diagnosis of mental status will be cleared up by such an instrument as the Vineland social maturity scale. (PsycINFO Database Record (c) 2012 APA, all rights reserved)