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Adolescent Development


Evan G. Graber

, DO, Sydney Kimmel Medical College

Last full review/revision Apr 2021| Content last modified Apr 2021

During adolescence, children become young adults. They undergo striking physical, intellectual, and emotional changes. However, the path to adulthood is not a straight line. Adolescents do not simply become steadily more and more like adults with time. Rather, adolescents alternate between acting like adults and acting like children. As adolescents develop, they gradually spend more time behaving as adults and less time behaving as children.

During adolescence, people develop a sense of who they are and learn to form intimate relationships with people who are not members of the family. Guiding adolescents through this intricate period of development can be a challenge for parents. Risk-taking (such as engaging in violence and binge drinking) is common among adolescents and causes severe health risks. Unhealthy behaviors such as smoking or drug use, which cause serious problems later in life, also typically begin in adolescence.

(See also Problems in Adolescents.)

Intellectual and Behavioral Development

In early adolescence, a child begins to develop the capacity for abstract, logical thought. This increased sophistication leads to an enhanced awareness of self and the ability to reflect on one’s own being. Because of the many noticeable physical changes of adolescence, this self-awareness often turns into self-consciousness, with an accompanying feeling of awkwardness. The adolescent also has a preoccupation with physical appearance and attractiveness and a heightened sensitivity to differences from peers.

In mid adolescence, the weight of making decisions about a future career gets increasingly heavy, and most adolescents do not have a clearly defined goal, although they gradually realize their areas of interest and talent. Parents must be aware of the adolescent’s capabilities and help the adolescent set realistic goals. Parents also must be prepared to identify roadblocks to learning, such as learning disabilities, attention problems, behavior problems, or inappropriate learning environments, which need to be corrected.

Adolescents also apply their new reflective capabilities to moral issues. Preadolescents understand right and wrong as fixed and absolute. Older adolescents often question standards of behavior and may reject traditions—to the consternation of parents. Ideally, this reflection culminates in the development and internalization of the adolescent’s own moral code.

Many adolescents begin to engage in risky behaviors, such as fast driving. Many adolescents begin to experiment sexually, and some may engage in risky sexual practices. Some adolescents may engage in illegal activities, such as theft and alcohol and drug use. Experts speculate that these behaviors occur in part because adolescents tend to overestimate their own abilities in preparation for leaving home. Recent studies of the nervous system also have shown that the parts of the brain that suppress impulses are not fully mature until early adulthood.

Emotional Development

During adolescence, the regions of the brain that control emotions develop and mature. This phase is characterized by seemingly spontaneous outbursts that can be challenging for parents and teachers who often receive the brunt. Adolescents gradually learn to suppress inappropriate thoughts and actions and replace them with goal-oriented behaviors.

A typical area of conflict is the adolescent’s normal desire to seek more freedom, which clashes with the parents’ instincts to protect their children from harm. Frustration caused by trying to grow in many directions is common. Communication can be challenging as parents and adolescents renegotiate their relationship. All of these challenges are accentuated when families face other stresses or parents have emotional difficulties of their own because adolescents continue to need parenting. Doctors can help open lines of communication by offering adolescents and parents sensible, practical, supportive advice.

Social and Psychologic Development

The family is the center of social life for children. During adolescence, the peer group begins to replace the family as the child’s primary social focus. Peer groups are often established because of distinctions in dress, appearance, attitudes, hobbies, interests, and other characteristics that may seem profound or trivial to outsiders. Initially, peer groups are usually same-sex but typically become mixed later in adolescence. These groups assume an importance to adolescents because they provide validation for the adolescent’s tentative choices and support in stressful situations.

Adolescents who find themselves without a peer group may develop intense feelings of being different and alienated. Although these feelings usually do not have permanent effects, they may worsen the potential for dysfunctional or antisocial behavior. At the other extreme, the peer group can assume too much importance, also resulting in antisocial behavior. Gang membership is more common when the home and social environments are unable to counterbalance the dysfunctional demands of a peer group.

Doctors should screen all adolescents for mental health disorders, such as depression, bipolar disorder, and anxiety. Mental health disorders increase in incidence during this stage of life and may result in suicidal thinking or behavior. Psychotic disorders, such as schizophrenia, although rare, most often come to attention during late adolescence. Eating disorders, such as anorexia nervosa and bulimia nervosa, are relatively common among girls and may be difficult to detect because adolescents go to great lengths to hide the behaviors and weight changes.

Substance use typically begins during adolescence. More than 70% of adolescents in the United States try alcohol before they graduate high school. Binge drinking is common and leads to both acute and chronic health risks. Research has shown that adolescents who start drinking alcohol at a young age are more likely to develop an alcohol use disorder as an adult. For example, adolescents who start drinking at age 13 are 5 times more likely to develop an alcohol use disorder than those who start drinking at age 21.

Almost 50% of U.S. adolescents try cigarettes, over 45% try electronic cigarettes (vapes), and more than 43% try marijuana while they are in high school. Use of other drugs is much less common, although misuse of prescription drugs, including drugs for pain and stimulants, is on the rise.

Parents can have a strong positive influence on their children by setting a good example (such as using alcohol in moderation and avoiding use of illicit drugs), sharing their values, and setting high expectations regarding staying away from drugs. Parents also should teach children that prescription drugs should be used only as directed by a doctor. All adolescents should be confidentially screened for substance use. Appropriate advice should be given as part of routine health care because even very brief interventions by doctors and health care practitioners have been shown to decrease substance use by adolescents.

Development of Sexuality

The start of sexual maturation (puberty) typically is accompanied by an interest in sexual anatomy, which may be a source of anxiety. As adolescents mature emotionally and sexually, they may begin to engage in sexual behaviors. Masturbation is common among girls and nearly universal among boys. Sexual experimentation with a partner often begins as touching or petting and may progress to oral, vaginal, or anal sex. By late adolescence, sexuality shifts from experimentation to being an expression of intimacy and sharing. Doctors should provide appropriate advice on safe-sex practices as part of routine health care and should screen all sexually active adolescents for sexually transmitted diseases.

As adolescents navigate their sexuality, they may also begin to question their sexual identity and gender identity.

  • Sex refers to a person's anatomy: male, female, or not clearly male or female (ambiguous genitals).
  • Sexual identity (also called sexual orientation) refers to the gender to which a person is sexually attracted, if any. There are many different sexual identities, such as heterosexual (attraction to the opposite gender), homosexual (attraction to the same gender), bisexual (attraction to both genders), and asexual (attraction to neither gender).
  • Gender identity is how people see themselves, whether male, female, or something else (sometimes called genderqueer, genderfluid, nonbinary, or agender), which may be somewhere in-between a combination of male and female, or may be neither, or may frequently change. Transgender is any gender identity in which people feel that the sex they were assigned at birth does not match their gender identity.
  • Gender expression is how people present themselves in public in terms of gender. It includes the way people dress, speak, wear their hair—in fact everything that people say and do that indicates masculinity or femininity.

Some adolescents struggle with sexual identity. They may be unsure of what they are feeling, but it is common for adolescents to be attracted to or have sexual thoughts about people of the same sex and people of the opposite sex. However, many adolescents who explore homosexual or bisexual relationships ultimately do not continue to be interested in same-sex relationships, whereas others never develop interest in opposite-sex relationships. Homosexuality, bisexuality, and asexuality are normal variations of human sexuality and are not disorders. Although it is not understood exactly why homosexual or bisexual feelings develop, experts do not think sexual or gender identities are something adolescents learn from their peers or the media or something they choose the same way they select an after-school activity or a career path. Adolescents who have a strong sense of their homosexual or bisexual identity may “come out” to their close friends or family members.

Adolescents may face many challenges as their sexual and gender identities develop. They may feel unwanted or unaccepted by family or peers if they express a certain sexual desire or a transgender identity. Such pressure (especially during a time when social acceptance is critically important) can cause severe stress. Fear of abandonment by parents, sometimes real, may lead to dishonest or at least incomplete communication between adolescents and their parents. These adolescents can also be taunted and bullied by their peers. Threats of physical violence should be taken seriously and reported to school officials or other authorities. The emotional development of these adolescents is best helped by supportive friends and family members.

Few elements of the human experience combine physical, intellectual, and emotional aspects as thoroughly as sexuality and all the feelings that go along with it. Helping adolescents put sexuality and gender identity into a healthy context is extremely important. Parents should share their values and expectations openly with their adolescents but be receptive and supportive as their child’s sexual and gender identities develop.

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