Most young people between nine and 15 years of age experience a rapid succession of physiological changes called the adolescence growth spurt. In girls, the adolescence growth spurt typically begins immediately after age 10. The first outward signs of adolescence in girls include increase in height, enlargement of the breasts and pelvis, as well as the appearance of hair on the pubic regions and in the armpits. Usually at age 13, adolescence in girls is marked by the onset of menstruation, which is called menarche. This signifies the initial release of a mature egg cell from the ovaries.
In human growth and development, adolescence is the stage between childhood and adulthood, usually from age 12 or 13 through age 19 or 21. It is characterized by social and psychological stages, as well as by physiological or biological changes. Depending on the type of culture that a person has, the rate of adolescence may be brief, prolonged, or even non-existent. For instance, the transition from childhood to adulthood in simple societies tends to be rapid and is characterized by rites of passage as prescribed by tradition. Growth in adolescence depends on increased hormonal secretions, as hormones induce the growth of sex organs to their mature size.
Adolescence in girls usually begins at 11 years of age, although some girls undergo this stage as early as age eight or nine, or as late as age 16 or 17. The typical increase in height is about 3 inches (7 cm) per year. Usually at age 15, girls have already reached their maximum height, with a body that has become slender quite abruptly and with the gradual emergence of the features of an adult face. Adolescence in girls is also marked by the enlargement of the pores of the skin, resulting in an increase in oily secretion that causes pimples to emerge. This is often aggravated by the occurrence of the menstrual cycle, the human female reproductive cycle.
Psychological development is also pronounced during the stages of adolescence in girls, with intelligence developing rapidly. Girls begin to develop their ability to infer and conclude, handle complex ideas, reason logically, and make connections between causes and effects. There are also emotional and personality changes that occur during adolescence in girls. The overall effects of all physical, mental, and social changes all contribute to how girls are molded to become adults. If they feel that they are not successful in meeting goals set by their parents, they usually reassess their motives and attitudes to ensure acceptance especially in the society in which they are in.
Identity formation also occurs during adolescence in girls. Young girls learn adult ways of behavior from their families. Conflicts, however, may occur due to differences in views. Meanwhile, the peer group helps girls undergo changes from being reliant on their families to being independent and socially mature individuals. This, however, may lead them to undergo risk-taking behaviors and activities.