The methodological potential of the principle of integrity in B.G. Ananiev's human study is considered. It is the epistemological basis of an integrated synthesis of human psychology in complex studies of its mental organization as well as in the interdisciplinary human studies. According to the results of human studies in ethnology, anthropology, psychology and sociology the forms of holistic manifestations of ethnicity as a physical type of individual and psychological type of the person in its external appearance, social perception and social interaction are determined. B.G. Ananiev's methodology of human study allows to consider all of the empirical phenomenology of the manifestation of ethnicity in the holistic construct of innate (individual), inborn (personality) and acquired (subjective) properties of the person and of society, the constellation of which constitutes the phenomenon of the model individuality. Individual features of the "physical type" in appearance are a significant basis of person's identification in social perception. In the process of people's perception of each other's appearance turns into a symbolic complex containing multiple property values of the object/ subject of knowledge as a partner in local and wider contexts of social interaction. This interaction is determined by the conditions of the natural, of subject and of social environment in which numerous ways to adapt to it and to oneself are formed. These methods are objectified in lifestyle, ecnomic activity, language, rituals, customs, traditions and other forms of ethnic culture. They represent the socio-psy- chological content of human relations in the form of mental behaviors and activities, which are formed in the family and contact groups through direct communication, according to the laws of the collective unconscious. For example, the interdisciplinary synthesis of the results of the cognition of ethnicity in ethnology, anthropology, psychology and sociology, reveals the heuristic potential of the methodology of B.G. Ananiev's human study. The scientific productivity of the integrated methodology for the synthesis expands the horizons of human cognition and determines the historical significance of B.G. Ananiev's contribution.