Adolescence definition: How psychologists define this major life stage

For some, adolescence may be one of the most memorable stages of life. You may associate this life stage with formative events, key people, and significant physical and emotional changes. Adolescence can be an exciting time, filled with substantial transitions and new connections. However, at the same time, these changes can be overwhelming. 

If you’re a parent or adolescent yourself, the following information is intended to help you understand the meaning and stages of adolescence while offering ways to support adolescents through this foundational period of life. 

Adolescence definition

According to the World Health Organization (WHO), adolescence is the phase of life between childhood and adulthood. During this life stage, individuals experience rapid physical, cognitive, and psychosocial growth, occurring around the ages of ten to 19. Key milestones may include:

• Learning to make decisions and healthily express feelings and thoughts
• Establishing patterns of behavior related to diet, exercise, substance use, and sexual activity, which lay the foundations of long-term health
• Forging new platonic and romantic relationships
• Exploring independence

By the end of adolescence, most teens complete physical development and reach reproductive maturity.

If you are struggling with substance use, contact the SAMHSA National Helpline at (800) 662-4357 to receive support and resources.

The three stages of adolescence

Adolescence can look slightly different for each individual, but teens may most commonly go through the following distinct stages of development. 

Early adolescence (Ages 10 to 13)

Early adolescents may notice the physical signs of puberty, including underarm and pubic hair. This stage may also correlate with breast development in those with a gynecological reproductive system and enlargement of the testicles in people with an androgynal reproductive system.   

Some youth notice significant physical changes during this phase, but others may experience more subtle or slower changes. On average, adolescents with gynecological systems start their period around age 12. However, the menstrual cycle can begin as early as eight years old. Adolescents with androgynal symptoms often start to experience physical changes one or two years later. 

Early adolescents may express curiosity as well as anxiety about their changing bodies. They may ask trusted adults about puberty and express other concerns about healthy development, simultaneously demanding more space. Throughout this process, supportive adults can respect their children’s boundaries and listen without judgment if or when their children decide to ask questions. 

Middle adolescence (Ages 14 to 17)

Middle-stage adolescents experience physical changes, including growth spurts, acne, and vocal changes. Adolescents with gynecological systems may start to have regular periods and reach their complete height and breast development.

This stage is also associated with more romantic and sexual activity. Middle adolescents may express more interest in sex, sexuality, and gender identity. Adolescents may spend less time with their families and invest more in platonic and romantic relationships as they explore these areas of life.

Compared to childhood and early adolescence, a middle adolescent may use less “black-and-white” thinking and engage in more abstract thinking. Still, there are many differences between the brain during adolescence and a mature adult brain, and the frontal lobes continue to develop well into early adulthood. While middle adolescents may be able to engage in more complex thinking, they may not always use their emerging reasoning skills. As a result, this stage is often associated with impulsive decision-making, which may lead to risky behaviors like substance use, sexual activity, and skipping school.  

Late adolescence (Ages 18 to 19)

In the final stage of adolescence, most teens have reached their full adult height and completed physical development. After finishing high school or another form of secondary education, they may begin to navigate the transition from the teenage years to adulthood. 

At this point in life, many adolescents have a stronger sense of their identity, values, and hopes for the future. While their brains are still maturing, they may have better impulse control and a more accurate assessment of risks and rewards. With this foundation, late adolescents can begin making informed decisions about the future, ideally with the support of family, friends, and other loved ones. 

Supporting your child through adolescence: Five tips for adults

Whether your child is just beginning adolescence or making their first adult decisions, you can support your child’s health at all stages of life. The following five tips apply to parents, caregivers, and other supportive adults who want to help teens flourish in adolescence and beyond.

Recognize their accomplishments

Adolescence can be a tumultuous and uncertain time. Adolescents may struggle to recognize their progress and accomplishments, especially when unsure about their identities and goals in life. As an adult, you can comfort and encourage adolescents by praising their efforts, achievements, and positive behaviors. A word of encouragement or genuine compliment can impact an adolescent’s self-esteem and belief in their abilities.

Talk to them about social media

Some parents may express concerns about their adolescent’s relationship with social media. In a digital world, your adolescent may rely heavily on social media for information, connection, and affirmation. 

While you may be unable to eliminate social media from your child’s world, you can talk to them about their actions online and teach them the basics of being a positive digital citizen. Like with face-to-face interactions, positive digital citizenship means interacting with others online in a safe, ethical, and respectful manner. 

Consider setting healthy examples like monitoring your own social media use, designating no-screen times and spaces in your home, and respecting your adolescent’s need for space. At the same time, you can encourage them to think critically about the long-term consequences of photos, videos, and other content they post. 

When working with your child instead of against them, you may foster a relaxed and respectful conversation about your child’s online presence so they can be comfortable sharing any questions or concerns related to social media. 

Support their self-expression

Adolescents are often known for their self-expression. They may dabble in a new style, dye their hair, or pursue a new interest at the urging of their friends. As your child explores new ways to express themselves, try to support their decisions and stay curious about their evolving interests, even if you don’t always understand them. 

Self-expression is a natural stage of adolescence. By accepting these changes, you may gain an opportunity to learn more about your child, ask thoughtful questions about their decisions, and grow closer as a result. You might notice that some of the choices they make in adolescence end up being parts of their adult personality later. Not all choices in adolescence are necessarily a phase.  

Learn more about developmental tasks

As they mature and develop, teens complete several “tasks,” achieving specific milestones that support their growth and development. The University of Texas Medical Branch divides these developmental tasks into the following four stages of psychosocial development: 

1. Body Image: Adolescents learn to accept their physical bodies and how to keep themselves healthy.
2. Independence: Adolescents become more self-sufficient as they age and begin preparing for their futures.
3. Peer Relations: Adolescents learn to get along with people from various backgrounds.
4. Identity: By the end of adolescence, young people may better understand their values and identities.

These stages don’t necessarily occur in order, and a person may continue to complete “tasks” related to these categories after adolescence. Still, you may find it helpful to refer to these stages, reflect on your adolescent’s progress, and support them as they work toward the next significant milestone. 

Consult a therapist

You may seek additional support and advice as you navigate adolescence with your teen. Adolescence can be a critical time for young people, but it can also be challenging for their parents and loved ones.

Parents may attend therapy with their child, partner, or individually during this time. Some people prefer in-person therapy, but a growing number of families and individuals prefer online therapy to work toward their mental health goals. Using a digital platform like BetterHelp for adults or TeenCounseling for teens aged 13 to 19, you can connect with a licensed therapist within a few days of completing a brief online questionnaire. Online therapy can be more cost-effective and allow you or your teen to attend therapy outside of standard business hours. 

Several studies show that online therapy can be as effective as in-person sessions, including a 2021 study of an online psychosocial group intervention for parents. During the six-week program, parents learned coping strategies rooted in cognitive-behavioral therapy (CBT) and acceptance and commitment therapy (ACT). The researchers found that parental anxiety and depression decreased significantly, and their use of adaptive coping skills also improved. 

Takeaway

Adolescence is one chapter of life, but this stage is often critical for children and their families. Learning the definition of adolescence is the first step to understanding adolescence. Afterward, you can apply this information to better understand and support the young people in your life.

If you’re looking for an expert to guide you along the way, therapy can be a valuable resource. Consider contacting a licensed therapist for further guidance and support as you and your child navigate adolescence and parenting challenges.