The general hypothesis of this study states that certain psychological traits which have their scores distributed continuously may actually have an underlying genetic dichotomy which is masked by various other effects. To be more precise, three specific hypotheses state for each variable that: (1) there is a similarity between parents and their children unexplained by similarity between the parents; (2) this similarity may be explained by hereditary components, and (3) these hereditary components are of the discrete or segregated type of inheritance. The population, consisting of 104 fathers and mothers and their teenage sons or daughters, was given eight psychological tests: Symbol Comparison, Word Association, Mental Arithmetic, Pitch Discrimination, Letter Concepts, Spelling, Identical Blocks, and English Vocabulary. Self-reports of height and weight were also obtained. These data were analyzed both by correlational methods and dichotomic analysis.