A battery of two verbal and two performance tests for adult morons is described. The scores are expressed in graphic form, and certain types of curves are found to be highly accurate in the prognosis of social adaptability. Curves which are unbiased indicate the best social prognosis; next come curves biased in favor of performance; irregular curves and those biased in favor of verbal tests are of bad prognostic import. The dispersion of abilities shown by the subjects is believed to be due mainly to affective factors. The principal non-cognitive processes affecting the various tests are discussed. (PsycINFO Database Record (c) 2006 APA, all rights reserved)