The younger generation has been given various nicknames such as 'teen-ager', 'apres la guerre', 'taiyozoku' (beat generation), and so on. Because, in any times this rising generation has been somewhat enigmatic from the adult's eyes. Some of them may reply that to them too, the adult has been always so enigmatic. However, it is not so strange that the preceding group on the course of unknown world of life looks enigmatic from the follower's eyes. Strange is that a certain period of life is so enigmatic to those who passed, through it and should know it.
There is no doubt about that the adolescence is a transition period of life located between the childhood and the adulthood. But an adolescent behaves sometimes so enigmatically that his behaviors can not be simply concluded as transitional phenomena or as responses to the so-called developmental tasks. We call it in a word 'youthfulness'. What is 'youthfulness'? Needless to refer to Mead's studies on the adolescent behavior in some primitive societies, recent some studies done by Flemming and others showed that behaviors of adolescents in modern societies are mostly effected by social-cultural factors. Phenomena of 'youthfulness, therefore, should be approached on the social stage. From this comes the view point which regards 'youthfulness' as a socially determined. 'role'. Young people behave so youthfully responding to the expect from the society in which they live. Of course, the expect meant here is not always onesidedly determined by adults but also by young people themselves. Thus, the possible discrepancy on mutual expects results the gap of generations which makes each other so enigmatic.
This paper reports a trial approach to this independent subject 'youthfulness', which was done especially for the purpose of making clear the phenomenon as a role-behairor taken by adolescents, in other words, to clear how the 'youthfulness' is socially phenomenalized among adolescents.