Physical Development

Puberty, or the attainment of sexual maturity, marks the end of childhood and signifies the beginning of adolescence; it is characterised by dramatic physical changes in both the overall rate of growth and in the development of sexual characteristics. Puberty is not a single, sudden event but is part of a gradual process. The hormones released during puberty bring about the development of primary and secondary sexual characteristics — primary sex characteristics being those directly related to reproduction, and secondary sex characteristics being other features or signs that indicate the attainment of sexual maturity. Pubertal changes in boys are marked by an acceleration in growth, the appearance of facial hair, and changes in voice; the growth spurt in boys generally begins around age 12 or 13. In girls, a rapid increase in height usually begins about two years before menarche, the onset of menstruation, with the growth spurt generally beginning around age 10 or 11. It is entirely normal for there to be variation in the pubertal sequence — among two boys, or two girls, of the same chronological age, one may complete the pubertal sequence well before the other has even begun it, and both genetics and environment play a part in this variation. For example, identical twins tend to reach menarche closer in time to each other than fraternal twins do (pointing to a genetic influence); on average, girls from more affluent families tend to go through menarche earlier than girls from poorer families (pointing to an environmental/nutritional influence); and historical trends show that the average age of menarche has been declining in industrialised nations, reflecting improvements in nutrition and advances in medical care over time.

Physical development during adolescence is also accompanied by a number of psychological changes. Around puberty, adolescents typically show an increase in interest in members of the opposite sex and in sexual matters, along with a new awareness of sexual feelings; this heightened attention to sexuality is caused by factors such as an individual's own growing awareness of the biological changes taking place in their body, along with the emphasis placed on sexuality by peers, parents, and the wider society. Even so, many adolescents lack adequate knowledge, or hold misconceptions, about sex and sexuality; since sex is a topic many parents find difficult to discuss with their children, adolescents often become secretive about their sexual concerns, which in turn makes open exchange of accurate information and communication more difficult. Concern over adolescent sexuality has become more intense in recent times because of the risk of HIV/AIDS and other sexually transmitted diseases. …