 Currently, it is appropriate to define adolescence as the period spanning ages 12 to 18.This is because people in this age group in the United States typically live at home with their parents, are undergoing pubertal changes, attend middle schools and high schools and are involved in a "school-based peer culture".All of these characteristics are no longer normative after the age of 18, and it is, therefore, considered inappropriate to call young adults "adolescence" or "late adolescence".