People's behavior forms their lifestyle. Leisure activities can be indicators of a person's lifestyle and value system. As leisure time grows in the more urbanized areas, the ways in which youths use that time becomes more important, especially for youths who are neither children and under strict tutelage of their parents nor are they old enough to be earning their living. Leisure time can be well spent in travels or in group artistic, social (e.g., volunteering in service organizations), intellectual, and physical activities, all of which can offer artistic, creative, intellectual, personal or cultural enrichment. Leisure time can also be squandered on such passive, spectator activities as television watching or 'loafing' at dances, parties, cafes, or other nondirected group activities, where the impetus to delinquency is nurtured through boredom and peer influence. While the availability of money can enable youths to take advantage of the more expensive types of leisure activity (travel or membership in special groups) and a higher level of education and a peer group that is so-oriented can lead or guide youths to more constructive forms of leisure activity, the school and home environments can also contribute positively to engaging youths in self-instructive and self-enriching activities. Instructors and educators must learn that education can be transmitted through recreation as well as it can be transmitted through classroom teaching. Extracurricular organizations such as the Scouts and youth associations should be developed in all areas, and particularly in high-rise apartment buildings where youths are in need of community structures. Research has shown that concerted efforts to directing youths' to leisure-time activities that are instructive and creative serve to reduce delinquency, prevent it altogether, and to reeducate youths toward constructive output of their energies. Four footnotes are provided. --in French.