Adolescent Behavior


From the ages of about 12–18, you can expect your child’s development to include many predictable physical and mental milestones—but also some changes that may cause them anxiety and confusion. Here are some things to look for during this transition, along with some advice on handling these many changes in adolescents, according to the National Institutes of Health.

During adolescence, children develop the ability to:

  • Understand abstract ideas (such as higher math concepts and philosophy), and develop moral concepts and views, including rights and privileges
  • Establish and maintain relationships by learning to share intimacy without feeling worried or inhibited
  • Begin to have a more mature sense of themselves and their purpose
  • Question old values without losing their identity
  • Seek independence and challenge authority figures

Physical Development

During adolescence, young people go through many changes as they move from childhood into physical maturity. Early prepubescent changes occur when the secondary sexual characteristics appear. These are traits that distinguish the two genders but are not directly a part of their reproductive system; for example, boys growing facial hair or girls’ hips growing wider. These physical changes, and the adolescent’s reaction to them, have an impact on young people’s emotional and sexual behavior. Learn more about adolescent sexual development and get parenting tips about sexuality.


The sudden and rapid physical changes that adolescents go through can make them very self-conscious, sensitive and worried about their own body changes. They may make painful comparisons about themselves with their peers.

Because physical changes may not occur on a smooth, regular schedule, adolescents may go through awkward stages, both about their appearance and physical coordination. Girls may be anxious if they are not ready for the beginning of their menstrual periods. Boys may worry if they do not know about nocturnal emissions.

During adolescence, it is normal for young people to begin to separate from their parents and establish their own identity. In some cases, this may occur without a problem from their parents and other family members. However, in some families, this normal adolescent rebellion may lead to conflict as the parents may try to keep control.

As adolescents pull away from their parents in search of their own identity, their friends become more important.

  • Their peer group may become a safe haven in which the adolescent can test new ideas.
  • In early adolescence, the peer group usually consists of nonromantic friendships, often including “cliques,” clubs or gangs. Members of the peer group often try to act alike, dress alike, have secret codes or rituals, and participate in the same activities.
  • As the youth moves into mid-adolescence (14–16 years) and beyond, the peer group expands to include romantic friendships.

In mid- to late adolescence, young people often feel the need to establish their sexual identity by becoming comfortable with their body and sexual feelings. Through romantic friendships, dating and experimenting, adolescents learn to express and receive intimate or sexual advances.

Adolescents often exhibit some common behaviors based on typical—though incorrect—assumptions:

  • “I am on stage.” Adolescents often assume other people’s attention is constantly centered on their appearance or actions. This over-the-top self-centeredness is normal, but it can be hard for parents and others to handle.
  • “It will never happen to me, only the other person.”Teens often wrongly assume that they won’t become pregnant or catch a sexually transmitted disease after having unprotected sex; cause a car crash while driving under the influence of alcohol or drugs (or texting), or any of the many other negative effects of risk-taking behaviors.

Learn more about safety, independence and power struggles.