Although girls undergo greater physical change during puberty than do boys, they tend to reach puberty earlier and take less time to reach maturity. Adolescence in young women begins around age 11 and continues through about age 16. In young men, the corresponding period begins about age 13 and continues through about age 18. After about age 14, males are, on the average, heavier and taller than females.
Most adolescents become sexually mature two or three years after puberty begins.
Hormonal changes awaken sexual feelings, and many adolescents have some sexual experience. Dating normally begins during mid-adolescence. Hormonal changes also account for the moodiness for which adolescents are well known. Adolescents who have difficulty adjusting to physical changes may become depressed or apathetic. Alternately, there are times when intense physical energy leads adolescents to unbounded enthusiasm for particular activities or causes.