This co-authored text seeks to examine adolescent functioning in the larger context of family and society. We will make our observation through our work in the « Maison de Solenn », an open adolescent treatment center. Is physiological criteria sufficient to define someone as an adolescent and to distinguish an adolescent from an adult ? Are today’s adolescents more precocious ? Must we consider them as adults based solely on the fact that they are bigger and stronger and cease to take into consideration the infantile part of every adolescent ?