The Teenage Brain: A mystery?

Teenagers. We often forget we were once teenagers ourselves. Their angst, impulsivity, and the crazy desire to live for fun makes them seem as if they are from another world. These characteristics are due to the teenage brain. The teenage brain undergoes a series of changes during cognitive development and is easily influenced by a number of factors. Let’s find out what those are.

The Teenage Brain: A mystery?
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Cognitive Development of the Teenage Brain

Cognitive development refers to the changes in the brain that allow an individual to learn. “Learning” entails not only acquiring basic knowledge, but the maturation of cognitive skills to assist in problem-solving, reasoning, and complex thinking. To do so, the brain produces new brain cells. These cells increase the amount of information one can take in. It is integral to the decision making process. The brain adapts to the environment, stimuli exposure, and heals injury by pruning—ridding of the cells that are infrequently used—and growing those that are. Brain connections are insulated with a protective myelin sheath. Different areas of the brain develop at varying rates.

Cognitive Abilities of the Teenage Brain

Adolescent years (12-18) are a delicate stage. Cognitive development of the teenage brain is not complete until the mid-20s. There is no wonder why teenagers are so impressionable! They are still developing a unique set of cognitive skills that enhance their learning.

  • Abstract Thought—Abstract thinking is thinking about possibilities. The teenage brain, after cognitive development, can think about concepts that cannot be seen or touched. Their thinking takes on a philosophical, futuristic approach.
  • Metacognition—Metacognition is “thinking about thinking.” This includes planning, analyzing, and understanding thoughts and decisions.
  • Advanced Reasoning—Advanced reasoning involves predicting. It is what allows teenagers to consider the outcomes of their decisions.
  • Language—As the teenage brain develops, they improve in language skills. Both written and oral communication improve. They become more advanced and can write, speak, and comprehend a higher vocabulary.
  • Memory—Recall and storing of information is greater in adolescence than it is during childhood.
  • Questioning—Teenagers tend to question every rule given by authority figures. The teenage brain is capable of extensive questioning regarding opinions, identity, plans, goals, society standards, and ethics amongst other topics.

Behavior and the Teenage Brain

A teen typically oscillates back and forth between mature and child-like behavior. This is because their brains are still developing. When entering the teenage stage of adolescents, key changes in the brain influence how they think, process emotions, and behave. They begin to enjoy new activities, socialize more with others outside of their family, and maybe even become a bit rebellious as they pursue their identities.

Behavioral characteristics are challenging rules and authority to assert their newfound independence. Their blatant act of defiance can instigate aggression, mood swings, and arguments. Teens tend to be impulsive, seeking pleasure that can potentially lead to risky behavior due to neural changes in the brain pathways. Increased levels of dopamine, a neurotransmitter in the nervous system, creates the desire for reward. The decision-making process is interrupted during development. Teenagers are less likely to think before they act, so risky behaviors sometimes include drugs, sex, fighting, and other dangers resulting from poor decision making.

Puberty and the Teenage Brain

Teenage brain changes occur with the onset of puberty—a physical process that matures the adult body and prepares it for sexual reproduction. Puberty is initiated by hormones. The brain undergoes its synaptic pruning and strengthening of connections between neurons once triggered by the release of certain hormones. While many of the behavioral changes result from social experiences, hormones affect the teenage brain too. For instance, the sex hormone testosterone drives the desire for higher social status, which is a priority for adolescents. Studies (Blakemore, 2010) emphasize the behavioral characteristic of sensation seeking that is also linked to puberty. Both males and females at later stages of puberty had higher levels of risky, sensation-seeking behaviors (i.e. drug use).

Differences Between the Adult and Teenage Brain

Physically, an adult and a teenager are near the same size. But when it comes to the brain, there are vast differences. The teenage brain relies on the amygdala. The amygdala is reactive, stimulating a strong emotional response. When making decisions and problem solving, a teenager relies mainly on emotions. An adult’s cognitive processes are carried out using the developed prefrontal cortex—the area of the brain that causes us to think prior to behaving. Thoughts and decisions of an adult are less reactive and more logical and rational.

Teenage Brain: Mental Disorders Affecting the Teenage Brain

Mood swings are not uncommon in teenagers. In fact, minor moodiness is healthy and is a sign of a developing teenage brain as it adapts to the stress of a changing body. Fluctuating hormone and neurotransmitter levels, which is how the nervous system communicates with brain cells, is bound to cause minor episodes of moodiness. However, extreme behavior differences are possibly indicative of a more serious disorder.

  • Depression—Persistent feelings of sadness, hopelessness, apathy, and a loss of interest in activities lasting two weeks or longer.
  • Generalized Anxiety Disorder—Ongoing, excessive worry over everyday matters (i.e. family, friends, finances, work, school, etc.). Symptoms prevent daily activities.
  • Social Phobias—Also called social anxiety disorder, social phobias lead to intense fear, insecurity, and anxiety with social interactions.
  • Eating Disorders—Conditions such as anorexia nervosa, bulimia nervosa, and binge eating disorder often arise in the teenage years. They are characterized by changes in eating habits like calorie restriction (i.e. anorexia), purging after meals, or excessive binge eating. Eating disorders can develop from poorly coping with the increased concern over appearances that teens experience.
  • Attention deficit-hyperactivity disorder (ADHD)—A mental disorder marked by inattention, impulsivity, and hyperactive behavior. It affects the ability to control behavior.
  • Bipolar Disorder—Rapid shifts in mood such as manic highs of happiness and energy followed by lows of sadness and hopelessness.

Any concern for a mental disorder should be discussed with a physician.

Sleep For A Healthy Teenage Brain

Teenagers are known for late nights and sleeping well into the afternoon. The change may appear sudden, but alterations in sleeping habits during the adolescent years is normal. The body releases melatonin, a hormone made in the brain to regulate the sleep cycle, at a different time of day.

The developing teenage brain requires eight to ten hours of sleep per night. A lack of sleep produces harmful effects like: poor concentration, memory impairment, moodiness, risky behavior, a shortened attention span, and many see a drop in academic performance. Inconsistent sleeping patterns are known to interfere with the learning process because the brain does not have adequate time for the growth of brain cells. Establishing a sleeping routine is key to healthy teenage brain development.

Social Influence On the Teenage Brain

Social influence is the influence of people on thoughts, feelings, and behavior. The teenage brain is prone to influence from others—particularly their peers. Brain regions like the underdeveloped prefrontal cortex are activated when a teen processes social information, whereas a fully developed adult brain does not exhibit such activity. The prefrontal cortex controls the brain’s response to reward and is activated by socialization; therefore proving social influence acts as a reward for the teen and is why they prioritize socialization and friendships.

Peer influence is generally associated with negative “peer pressure.” A teen accepting a cigarette from a peer in order to feel accepted is a prime example of peer pressure. However, social influence can be both positive and negative. fMRI studies reveal that “adolescents made fewer risky choices in the presence of low-risk peers compared to high-risk peers” (Telzer et al., 2018). If the teenager is surrounded by positive influences, then positive social influence will result.

The Impact of Social Media on the Teenage Brain

In modern-day society, it is rare to see a teenager not attached to their phones. Through technology, they have the world at their fingertips. Social media comprises a large portion of a teenager’s daily routine. Using accounts like Facebook, Instagram, and Twitter, as well as communicating through text messaging, teens are connected to friends, family, and virtual strangers alike. Although social media does have its benefits, survey results found that Snapchat, Facebook, Twitter, and Instagram are associated with teen depression, anxiety, poor body image, and loneliness.

The Teenage Brain: A mystery?
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These feelings are related to physiological reactions in the brain. For example, the Journal of Psychological Science reports fMRI studies investigating the teenage brain and social media. Teenagers who witnessed large amounts of social media likes manifested brain activity in the reward circuits—an area sensitive during adolescence. The likes were randomly assigned by the researchers, which depicts the added power of peer pressure.

Alcohol and Substances and the Teenage Brain

Despite the legal age for alcohol consumption, teenagers often experiment with alcohol. They are pleasure seekers. During a time when their behavior is already impulsive, teenagers initially begin drinking as a way to be accepted by their peers, to enjoy themselves partying, or to pass leisure time. Statistics from the Centers for Disease Control and Prevention (CDC) prove one in four high school students engage in binge drinking—drinking up to five alcoholic beverages within the span of hours. The consequences of alcohol consumption have irreversible effects on the brain.

The frontal regions of the brain are less developed in teenagers. The frontal lobe is the area of the brain controlling the weighing of risks versus rewards essential for decision making. An underdeveloped frontal lobe decreases the likelihood of inhibiting impulsive behaviors (i.e. alcohol consumption) and increases their susceptibility to the negative effects of drinking. The hippocampus, the part of the brain responsible for learning, is also impacted by alcohol. Teenage brains exposed to alcohol display a larger loss of gray matter, which leads to poor memory, decreased academic performance, and deficits in attention. Experts from Duke University further report a smaller amygdala in teenagers who consume alcohol as evidence through studies.

How Parents Can Promote Teenage Brain Development

Teenage brain development is not the sole responsibility of the teen. The brain is significantly affected by stimuli in the environment. Prominent figures in the teen’s environment, such as parents, guardians, family, and friends, also have a role in promoting healthy development.

  • Encourage Hobbies—Hobbies, whether sports, music, or art, develop key brain skills and serve as an outlet to vent pent up emotions.
  • Discuss Decisions—Decision making is a challenge to the teenage brain. Talk about the teen’s decisions together, as this will give them the guidance to feel confident in their decisions.  
  • Modeling—As mentioned previously, the teenage brain is very impressionable. Be a positive role model. Behave according to the standards set for them.
  • Set Boundaries—Teenagers test their limits. Setting boundaries gives them an outline for appropriate behavior.
  • Reward Positive Behavior—Good behavior equals good outcomes. Rewarding positive behavior promotes teenage brain development because it causes the teen to associate patterns of healthy behavior with outcomes that will better their lives.
  • Healthy Habits—Sleep and nutrition are important for teenage brain development. Provide them with balanced nutrition and a consistent sleep schedule.
  • New Opportunities—Opportunities in academics, socialization, and more presents the chance for learning new skills and information.


Blakemore, S. J., Burnett, S., & Dahl, R. E. (2010). The role of puberty in the developing adolescent brain. Human brain mapping31(6), 926–933.

Paturel, A. (2012). The Effects of Drinking on the Teenage Brain. Brain & Life. Retrieved from

Telzer, E. H., van Hoorn, J., Rogers, C. R., & Do, K. T. (2018). Social Influence on Positive Youth Development: A Developmental Neuroscience Perspective. Advances in child development and behavior, 54, 215–258.

Wolpert, S. (2016). The teenage brain on social media. Retrieved from

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