Besides mentioning the method of finding out the influences of heredity and environment by means of studying monozygotic twins and a simple factor analysis by means of the dispersion complex according to N. A. Plochinski, the author submits a proposal for finding out special models. He regards these models as complexes of symptomatological signs and their causes (diagnosis) complexes of these sings and causes (diagnosis) and the future development of the child and complexes between diagnoses and educational influence. The aim of finding out the degree of educatability is not to differentiate the factor of heredity from that of environment, because, man being a phenotype, the two components cannot be separated. However, on the basis of previous development, it is important to determine development curves and predict the development of personality. Certain mathematical processes, such as seeking the mathematical function, may serve here as an auxiliary method. The outlined tasks are rather extensive and will require a number of special researches. To determine the degree of educatability in rough outline at least, the following factors are thought to be the most important: intellectual aptitudes, motor responses and social adaptability. The author gives various types of educatability based on various levels of these three factors. The author also gives the economic consequences of solving the problem & educatability of the youth.