Puberty to adolescence
Degas’ painting «Young Spartans exercising» is based on the writings of Plutarch, who tells about the ancient Spartan legislator Lycurgus. Lycurgus urged the Spartan girls to engage in wrestling. Here the adolescent girls urge the boys to fight. The girls’ entry into adolescence is visible in their development of breasts and other secondary sexual characteristics (the primary sexual characteristics are presence of ovaries or testes in the fetus and neonate). Near the end of the juvenile period girls and boys undergo a series of hormonal changes that are called «puberty». The biological changes of puberty begin in the brain and involve those brain centers that regulate sexual maturation. This brings about changes in anatomy, behavior, social interests, emotional attitudes, and cultural values. In the painting above some of these changes, in addition to breast development of girls, are the muscular development of boys and the renewed interest of the sexes in each other. Both boys and girls are experiencing a rapid increase in the rate of growth in height, called the adolescent growth spurt. Due to the biocultural nature of the puberty transition, there is a long history of research and scholarship by anthropologists, sociologists, psychologists, life history biologists, physicians, epidemiologists, and other human scientists, as well as economists and philosophers. Given this interest it may be surprising to know that puberty is an event of relatively short duration, only 1 to 2 months, followed by the adolescent stage which lasts for years. Despite its short duration the puberty transition takes the person from the immaturity of the child and juvenile to an incipient adult-like body and behavior. [Barry Bogin]