Development of the human body used to approximately judge a child's age based on physical development. Puberty is the process of physical changes through which a child's body matures into an adult body capable of sexual reproduction. It is initiated by hormonal signals from the brain to the gonads: the ovaries in a girl, the testes in a boy. In response to the signals, the gonads produce hormones that stimulate libido and the growth, function, and transformation of the brain, bones, muscle, blood, skin, hair, breasts, and sex organs. Physical growth—height and weight—accelerates in the first half of puberty and is completed when an adult
Society for the Scientific Study of Sexuality professional members. Society for the Scientific Study of Sexuality The Society for the Scientific Study of Sexuality (SSSS, or "quad-S"), formed in 1957, is a non-profit, international professional membership organization, based in the United States, that says it is "the oldest professional society dedicated to the advancement of knowledge about sexuality." It reports to have more than 1,000 members and has a quarterly newsletter, "Sexual Science". It produces two other publications: According to its website, SSSS was established in 1957 by psychologist Albert Ellis to encourage the rigorous, systematic study of sexuality. In 1980, organizer Robert Francoeur invited Philadelphia biologist