title: The Kendler levels--of--functioning theory: comments and an alternative schema.
mesh_terms: D000293:Adolescent; D000328:Adult; D001245:Association Learning; D002648:Child; D002657:Child Development; D002675:Child, Preschool; D003071:Cognition; D003118:Color Perception; D003210:Concept Formation; D003213:Conditioning, Psychological; D004193:Discrimination Learning; D005556:Form Perception; D006801:Humans; D007223:Infant; D011340:Problem Solving; D011582:Psychological Theory; D012106:Research; D012858:Size Perception; D014796:Visual Perception