Table 2 Adolescence in boys and girls manifests differently with regard to their actual fertility.

Become fertile approximately 2 years after onset of growth spurt; 1 year before peak height velocity

Completed half their breast and pubic hair development by peak height velocity; menarche approximately 1 year after peak height velocity

Remain juvenile in body hair, stature, muscularity and voice

Appear feminine, while remain infertile

Muscle spurt and adult stature still four years away; approximately 18 years

Adult frequency of ovulation and adult size of birth canal; approximately age 18 years

Learn adult social roles while sexually mature, but not perceived mature by adults

Learn adult social roles while infertile, but perceived by adults as mature