RESUMO
Along with language, socialization is a unique feature of the human being. There is a continuous debate regarding whether the development of socialization is innate, and conducted by the environment in the growing process, or the result of the interaction of both aspects. If socialization is the result of the interaction with the environment or is an acquired developmental process, the following question rises. "Is there a 'critical period' for the development of socialization?" Although there are a huge number of studies seeking for treatment and solutions for developmental delay or deficits of socialization, it is very complicated question to answer. Historical figures such as 'Hugh Blair' of Borgue in England, and 'the wild boy of Aveyron' in France, seem to have innate socialization deficits. Nowadays patients with non-verbal learning disorder, social communication disorder, or autism spectrum disorder seem to have genetic defects. On the other hand, Harry Harlow's monkey experiments, hikikomori of Japan, Romanian orphans and patients with reactive attachment disorder seem to display social deficits due to environmental factors. However, it is not easy to clearly draw a line between innate or acquired factors. Therefore, rather than subdividing the diseases for etiological and pathophysiological approach to heterogenous groups with the common denominator of social deficit, and for the research of pathophysiology and treatment development, the authors suggest a comprehensive concept of "social dysfunction spectrum."