Adolescence (Psychology)

The period of transition in which a child matures into an adult. The beginning of human adolescence is marked by a growth spurt. This spurt usually happens at the age of 12 for girls and is accompanied by numerous physical changes (e.g., the development of breasts and growth of pubic hair, onset of menstruation). For boys, this growth spurt begins generally at the age of 14, also accompanied by a multitude of physical changes (e.g., enlarging testes, pubic hair, facial hair, first ejaculation, voice deepening). By the end of adolescence, females are menstruating and males are producing live sperm, signifying sexual maturity. Adolescence is also marked by various psychological changes and challenges. Young people develop abstract thinking abilities and a clearer sense of psychological (and ethnic) identity, and they advance in their moral reasoning. Independence from parents and peer groups become important concerns. Peer groups usually have a positive effect when providing emotional support and can at times be more important than parents. Several developmental stage models have addressed the importance of adolescence in human development. In Sigmund Freud's model, adolescence marks the “genital phase” of psychosexual development, while for Jean Piaget, who focused on cognitive development, it is the “formal-operative stage.” Erik Erikson, in his theory of psychosocial development, identified the identity crisis as the central aspect of adolescence. For more information, see Lerner and Steinberg (2004).