The term adolescence generally refers to the developmental period between childhood and adulthood. Although this transitional period was recognized by ancient Romans, Greeks and Egyptians, the concept did not exist until the mid nineteenth century.
The increased urbanization led to social and legal reforms which contributed to the social acceptance of adolescence as a stage of development. These reforms include the following:
Child labour laws removed children and adolescents from factories and work places.
Changes in criminal laws allowed courts to treat juveniles differently from adults. Children and adolescents are not subject to the same legal procedures and punishments as the adults.
Mandatory public education placed large number of young people into schools and formally separated them from adults. Additionally the age graded school system separated children from adolescents.
In the 20th century, as technology advanced, increasingly specialized skills were demanded from workers. More extensive and finely tuned education and training were needed to produce highly skilled workers and these pressures continued to expand the time period between work and school became less obvious.
Postponing adult responsibilities give young people increased opportunities to explore different roles and values. Extending adolescence also has some negative consequences like it makes career choices more difficult for many adolescents. If the link between school and work becomes less obvious, longer dependency on parents may contribute to family conflict.