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 Psychological Study of Social Issues ways, including active engagement in the scientific study of human behavior in critical social situations, sharing the results of that research in scholarly settings, and providing relevant research findings to those engaged in developing public policy. SPSSI members are concerned with both U.S. and international issues, and SPSSI has been affiliated with the United Nations as a Non-Governmental Organization (NGO) since 1987. While SPSSI has focused primarily on U.S. policy in the past, its international membership is constantly growing and international issues have become a larger part of its work. SPSSI writes policy briefs, sponsors advocacy days, and trains its