Not an “Attitude” but a Brain Under Construction: The Biology Behind Your Teen’s Behavior

Jan R. Kerchner, MBA, CEP

(#1 in a 4 Part series)

If you’ve ever wondered how your child who aced a calculus test can also forget about soccer practice, or why a minor discussion can trigger a full emotional storm, you’re not imagining things. Adolescence is one of the most dramatic periods of biological change your child will ever go through, second only to infancy. Understanding what’s actually happening in their brain and body doesn’t excuse every eye-roll or slammed door, but it does explain a lot. And that understanding is the foundation for everything else in this series.

This four-part series draws on current neuroscience and developmental psychology to explain what's actually driving your teen's behavior, so that, as a parent, you can respond to who they really are!

Article 1 of 4: Understanding Your Teen’s Biology

A Brain Under Construction:

“Feel it now” and “think it through later” are not character flaws. It’s biology.

The teenage brain isn't just a smaller, less experienced version of an adult brain; it's a brain still being actively built. Two systems are developing on very different timelines, the reward system and the cognitive control system.

Laurence Steinberg, professor emeritus at Temple University and one of the field’s most cited researchers on adolescent decision-making, has spent decades documenting this exact gap. His work shows that the brain’s socio-emotional reward system is reconfigured early and intensely during adolescence, while the cognitive control system in the prefrontal cortex, responsible for judgment, impulse control, and planning, matures more gradually, over time, continuing to develop into the mid-twenties.

Neuroimaging researchers Adriana Galván at UCLA and Beatriz Luna at the University of Pittsburgh have used brain scans to map this gap directly, and their more recent work sharpens the picture. Luna’s 2023 study, published in Nature Communications, tracked executive function maturation from adolescence into adulthood and confirmed that cognitive control develops along a gradual, predictable trajectory that isn’t fully adult-like until the twenties. Galván, now co-director of UCLA’s Center for the Developing Adolescent, describes adolescents as “strategic risk-takers” whose willingness to explore, even when it looks reckless to adults, is part of what allows them to learn through trial and error. Together, their research shows that teens are capable of adult-like self-control in a calm moment but can’t yet reliably summon it under pressure, especially in front of peers. That’s part of why a teen can understand a rule perfectly well in a calm conversation and still break it in the heat of the moment with friends.

The good news is that during this same period, the brain is constantly rewiring itself according to the demands placed on it. Because the adolescent brain is unusually plastic, it’s also unusually responsive to new challenges. Academic engagement, physical activity, and creative pursuits like music or art don’t just fill time; they help strengthen the very circuits that are under construction. Science journalist Matt Richtel captures this well in his recent book on adolescence, How We Grow Up: teens are navigating a "neurological mismatch" between an ultra-stimulating modern world and a brain that's still under construction. That's a lot to adjust to, every… single… day.

When Puberty Happens Matters as Much as What Happens

Puberty gets treated as a single event, “the talk,” a growth spurt, a box to check. But it’s really a years-long process that touches nearly every aspect of development at once: physical, hormonal, cognitive, and social.

One thing that matters enormously and gets little attention is timing. Kids don’t all go through puberty on the same schedule, and where a teen lands relative to their peers carries real psychological weight. George Patton, the Australian psychiatric epidemiologist who chaired the influential 2016 Lancet Commission on Adolescent Health and Wellbeing, built much of his research career studying how the timing and pattern of puberty influence adolescent mental health over the long term. His large cohort studies reinforced what smaller studies had suggested: early-maturing girls, in particular, face higher rates of anxiety and depressive symptoms, often because their bodies are maturing before their social and emotional skills have caught up. Some research also points to elevated risk for late-maturing boys, who can feel socially out of step in the opposite direction.

Boys face a version of this too, just flipped. A 2025 UK cohort study tracking more than 4,600 boys found that early maturers had significantly higher odds of depression by age 18. Other research points to similar risks for late-maturing boys, who can feel just as out of step with peers, just for the opposite reason.

It’s not really about the body itself. It’s about the mismatch, looking older or younger than you feel, made harder by constant comparison with peers. A teen who "looks 16" at 12, or “looks 12” at 16, gets treated like someone older or younger than they really are just based on how they look.

What this means for parents: If your teen seems unusually sensitive about their body, their looks, or where they “fit” among friends, that sensitivity is developmentally real. It’s not vanity and it’s not drama.

The Sleep Shift

Here’s one of the more counterintuitive facts of adolescence: your teen’s biological clock actually shifts during puberty. This isn’t a discipline issue or a result of too much screen time (though screens don’t help). It’s hormonal.

Sleep researchers have documented that near or during puberty, the release of melatonin, the hormone that signals the brain it’s time to sleep, actually shifts to later in the evening, and the whole sleep-wake cycle moves with it. The result is a biological tendency to fall asleep later and wake up later, often by an hour or two compared to childhood patterns. Unfortunately, this shift collides head-on with early school start times, leaving many teens chronically sleep deprived during the school year.

There’s another layer to this that most parents never hear about: Sleep isn’t just when teens recover from their day; it’s also when much of the biological changes of puberty happen. The hormones that drive pubertal development are released in pulses roughly every 90 to 120 minutes, largely clustered during nighttime sleep rather than waking hours. Why the body ties this hormonal pulsing so tightly to sleep isn’t fully understood. Adriana Galván, the UCLA neuroscientist referenced earlier, is one of the researchers actively studying this intersection, examining how sleep, hormones, and adolescent mental health interact and shape each other. It’s a reminder that a teen’s sleep isn’t just downtime; for a body in the middle of puberty, it may be among the most biologically active times of their day.

This matters far beyond grogginess. Sleep deprivation directly affects emotional regulation, impulse control, and academic performance, which are the very systems already under strain from uneven brain development. A sleep-deprived teen isn’t just tired; they’re operating with even less access to the prefrontal “brakes” that are still under construction!

What this means for parents: consistent sleep and wake times, dimmer light in the evening, and protecting weekend sleep from swinging too wildly all help. But so does simply understanding that “I can’t fall asleep before midnight” may be a biological reality rather than an excuse.

The Reframe

None of this is a free pass. Teens still need boundaries, expectations, and consequences. But there’s a real difference between disciplining a teen as if they’re choosing to be difficult, and guiding a teen who is genuinely still building the hardware for self-regulation.

The parents who navigate adolescence most effectively tend to hold both truths at once: This behavior isn’t fully in their control yet, and I still expect them to grow toward being able to control it. That’s not permissiveness. It’s developmentally informed parenting, and it’s the foundation for the next three articles in this series: independence, emotional regulation, and identity.

Next in the series: “The Push for Independence” — why your teen’s pulling away is a sign of healthy development, not a rejection of you.

Sources

Steinberg, L., Age of Opportunity: Lessons from the New Science of Adolescence — dual systems model of adolescent reward sensitivity vs. cognitive control
Eagleman, D., Livewired: The Inside Story of the Ever-Changing Brain (2020)
Galván, A., The Beautiful Adolescent Brain: An Evolutionary Developmental Perspective, Annals of the New York Academy of Sciences (2025)
Galván, A., interview, Embracing Teens as Strategic Risk-Takers, UCLA Center for the Developing Adolescent (2024)
Richtel, M., How We Grow Up: Understanding Adolescence (2025)
Patton, G.C. et al., Our Future: A Lancet Commission on Adolescent Health and Wellbeing, The Lancet (2016); Patton’s Victorian Adolescent Health Cohort Study on pubertal timing and mental health
Ward et al. (2025), Pubertal Timing, Depressive Symptoms and Depression in Adolescent Males: A Prospective Cohort Study, Psychological Medicine — ALSPAC UK birth cohort (N=4,664 boys) on early pubertal timing and depression risk by age 18
American Academy of Sleep Medicine / CDC, Teenagers: Sleep Patterns and School Performance
Crowley, S.J., Acebo, C., & Carskadon, M.A., Sleep, Circadian Rhythms, and Delayed Phase in Adolescence
Shaw, N.D. et al., Insights into Puberty: The Relationship between Sleep Stages and Pulsatile LH Secretion, Journal of Clinical Endocrinology & Metabolism

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Career Preparation as a Selection Factor

By Jan Kerchner • May 27, 2026

Before You Choose a College, Ask This One Question: "How Will You Help Me Get Hired?" Choosing a college is one of the biggest decisions of your life and many students don't realize until several years later that they were asking the wrong questions. Their focus was on campus life, rankings, sports, and location, while overlooking the factor that matters most after graduation: career preparation. Here’s the reality: According to the 2026 Job Outlook Report from the National Association of Colleges and Employers (NACE ), nearly 70% of employers now use skills-based hiring. They’re not just looking at your diploma; they’re asking, “Can you actually do the job?” And what's the number one thing employers look for when scanning your resume? Whether you've interned with them. The second? Whether you've interned in their industry. Both answers point to the same truth: When you can prove your skills through real experience, you become the candidate employers feel confident choosing. NACE's report drives this home further: 74% of employers want college graduates to have experiential learning or work experience before they walk through the door for an interview. So, what does this mean when you're researching colleges? Dorms, college life, dining halls are important, BUT, start asking: What internship placement programs does your school offer? Do you have employer partnerships in my field? Can I earn industry-recognized certificates or micro-credentials alongside my degree? What percentage of students graduate with real work experience? Colleges worth your investment are the ones actively building bridges between the classroom and your career. Internships, co-ops, apprenticeships, and credentials aren't extras; they're the whole point. Choose a college that prepares you to get hired, not just to graduate. Employers are looking for students with real experience. Make sure your college is helping you build it.

Woman with light brown hair writing on paper with a red pen, wearing a black and white checkered shirt.

Should Your Student Aim for an Ivy League or Ivy+ College? What Parents Need to Consider

By Jan Kershner • February 20, 2026

Should your student aim for an Ivy League or Ivy+ college? Learn what parents should consider about fit, majors, early planning, and long-term success.

FRESHMEN AND SOPHOMORES, TOO EARLY TO START COLLEGE PLANNING? ABSOLUTELY……...NOT!

By Jan Kerchner • October 30, 2025

5 Reasons to Begin College Planning Early As a parent of a high school freshman or sophomore, you may think that college and career planning can wait until junior or senior year. However, the truth is, the earlier your student begins exploring interests, planning classes, engaging in meaningful community service and planning their future, the better positioned they’ll be for success in the college admission process… and they will be less stressed! With more than 3,000 colleges across the country and a world full of diverse career options, the opportunities can feel overwhelming for a teenager. Starting early gives your student the clarity and direction they need to excel academically, get involved in meaningful activities, and build a strong foundation for college and career pathways. Here’s why starting early is so important: 1. It helps students discover who they are and what they are truly interested in! The early years of high school are a time of self-exploration and growth. Other than infancy, these are the years of greatest personal and physical development. They are exploring who they are, who they want to be, AND it is when their brains are going through a significant pruning process which is determined by the parts of the brain they are using the most. Consequently, choices of activities and academics have a significant impact! By starting career exploration and college planning early, students can explore a variety of activities, from clubs and sports to volunteer opportunities and internships. They can find out what excites them, what they’re passionate about, and where their talents lie. The earlier they discover what they love, the more motivated they will be to pursue those passions throughout high school and college. This isn’t just about building a resume for college applications, it’s about helping students figure out what makes them tick. When students find something they are genuinely interested in, they are more likely to stay engaged and dedicated, which can lead to leadership roles and long-term accomplishments. 2. It allows time to build a stronger college application profile. For students aiming for highly competitive colleges, the time to start is now ! Many parents and students assume they can wait until junior year to focus on college prep, but in reality, this is too late. Competitive colleges receive hundreds, if not thousands, of applications from students with 4.0+ GPAs and strong test scores. How does a student differentiate himself or herself? Find a passion, pursue it with intensity, take additional classes, and master skills in order to have the credentials and experience these colleges are looking for by the time they submit their college applications. What credentials? Winning state or national competitions, conducting research with a college professor, developing a non-profit for their community, starting a business, developing a computer camp for kids, or writing a computer program. Starting early gives your student the chance to: Build depth in their interests or explore new ones : Competitive colleges want to see sustained involvement in a few key areas, not just a laundry list of activities. By starting early, your student can explore, commit to, and eventually take on leadership roles in activities that align with their passions. Gain impressive leadership positions : Colleges look for students who have taken initiative and shown leadership. By getting involved early, students have the chance to become leaders in clubs, sports teams, and other extracurriculars—showing their dedication and ability to lead. Make a lasting impression on teachers : Starting early allows your child to form meaningful relationships with teachers, who will eventually write their letters of recommendation. A strong, personalized letter from a teacher who has known your student for years and can attest to his or her intellectual curiosity can make all the difference in the admissions process. 3. It teaches time management, organizational skills, and planning! High school can be busy, and it can be tempting for younger students to put less emphasis on their future during their first couple of years. However, once junior year hits, the pressure ramps up with more challenging coursework, standardized tests, and college applications. By beginning career and college planning early, students learn valuable time management and organizational skills. They’ll get used to balancing academics, extracurriculars, volunteer work, and part-time jobs—skills that will serve them well throughout high school and in their future careers. 4. It opens doors to internships and volunteer opportunities! Some of the best opportunities- whether internships, summer programs, or community service roles—are available to students who start thinking about their future early. These experiences not only help build a strong college application, but they also provide valuable real-world exposure. Whether your student is interested in medicine, engineering, business, journalism, or the arts, internships and volunteering can help them gain insights into potential career paths while building valuable skills and relationships. By pursuing these opportunities early, students have a head start in finding meaningful experiences that will shape their future. 5. It helps students take ownership of their future! The earlier students begin thinking about their goals, the more time they have to align their high school experiences with their aspirations. This might mean taking certain AP, IB, or honors classes; seeking out internships; or developing skills outside of the classroom. By the time they’re ready to apply to college, they’ll have a clearer sense of who they are, where they want to go, how to get there, and they have the sense of accomplishment of making it happen! Final Thoughts While college and career planning may seem like a distant concern for many freshmen and sophomores, the truth is that the earlier a student begins the process, the more opportunities they’ll have to explore, grow, and succeed. By starting early, students set themselves up for success in high school, define their pathway to college, and gain the tools they need to grow and develop into a responsible, well-educated, and successful individual.

The Biggest Mistake Families Make: Not Starting College Planning in 9th Grade

By Jan Kerchner • October 29, 2025

Why early planning builds confidence, direction, and a stronger college application Many families assume college planning starts in junior year, but the most successful students begin much earlier. In fact, it is critical to begin in 9 th grade to build the foundation for college success. Starting in 9th grade isn’t about rushing; it’s about giving students the time to explore, engage, and grow with purpose. Early planning allows students to develop depth and consistency in their activities. Rather than joining a dozen clubs at the last minute, students who start early can identify a few meaningful interests, build skills, and take on leadership roles by 11th or 12th grade. Colleges value sustained involvement and authentic passion far more than a long list of short-term activities. Beginning early also helps students uncover academic and career interests. Freshman year is the perfect time to sample electives, complete interest inventories, or shadow professionals. These discoveries guide intentional course planning throughout high school, enabling students to advance to honors, AP, or IB classes. Many students also enrich their learning with dual enrollment or summer pre-college programs, experiences that strengthen transcripts and expand their horizons. Equally important, early planning allows time to develop strong study skills and learning strategies tailored to each student’s unique style. By building effective habits early, students are better prepared for the academic challenges ahead. Starting the college journey in 9th grade isn’t about checking boxes; it’s about building foundations . It provides time to explore, engage deeply, and enrich both academic and personal growth. Plan. Prepare. Thrive. At The College Blueprint , we guide students to design intentional four-year plans, building confidence, leadership, and purpose from the first year of high school. Learn more at www.thecollegeblueprint.com