Puberty and adolescence as important periods of youth are described in their form and relationship to society. The essential contents of this developmental period are: 1. breakthrough of ego-development, 2. awareness of genital sexuality, 3. conquest and keeping of the place one belongs in society. The manifestations of these developmental phases are shaped by biological somatic, psychological and social factors which have changed during the course of time in a more or less rapid or slowly progressive way. Crises during the most significant developmental periods of the youngsters reflect also the crises of the society.