The Adolescent Brain Revealed: Unpacking 30 Years of Laurence Steinberg's Key Findings
By Jack Vaughan
When it comes to the trials and tribulations of adolescence — it seems like everyone has an opinion. We tend to dismiss teenage behavior as "just a phase," attribute it to "raging hormones," or blame it on poor parenting. But what if our understanding of the teenage brain is incomplete?
For over three decades, Dr. Laurence Steinberg—Distinguished University Professor of Psychology and Neuroscience at Temple University—has been systematically dismantling our misconceptions about adolescence. Through nearly 500 published articles and groundbreaking research that has influenced U.S. Supreme Court decisions, Steinberg has revealed a profound truth: the adolescent brain isn't broken or defective, it's specialized for crucial developmental tasks.
Steinberg’s Dual Systems Model: Gas Pedal and Brakes
Steinberg's most influential contribution to adolescent science is the dual systems model. The model, first articulated in 2008, posits that increased risk-taking during adolescence results from a combination of heightened reward sensitivity and immature impulse control. These two capacities develop along dramatically different timetables.
As Steinberg describes it: "There is a time lag between the activation of brain systems that excite our emotions and impulses and the maturation of brain systems that allow us to check these feelings and urgings—it's like driving a car with a sensitive gas pedal and bad brakes."
The first system—the socio-emotional incentive processing system—is localized mainly in the ventral striatum and ventromedial prefrontal cortex. This is the brain's reward center, and it undergoes dramatic remodeling in early adolescence that have been linked to increases in reward-seeking and sensation-seeking more generally.
It makes perfect evolutionary sense that adolescents are more motivated by rewards, more oriented toward sensation-seeking, and more willing to take risks when they are supposed to leave the natal environment, establish independence, and seek out mates. This isn't a design flaw—it's a developmental feature.
The second system—the cognitive control system—is localized mainly in lateral prefrontal, parietal, and anterior cingulate cortices. This system supports planning, response inhibition, impulse control, and future orientation. Unlike the reward system, the cognitive control system develops gradually and linearly, with improvements continuing well into the mid-20s.
The Evidence: What the Research Actually Shows
In order to test the dual systems hypothesis, Steinberg and his colleagues conducted a large cross-sectional study of 935 individuals between the ages of 10 and 30.
Reward sensitivity, preference for immediate rewards, and sensation-seeking follow an inverted U-shaped function — they increase between preadolescence and mid-adolescence, peak between ages 14 and 16, and then decline.
In contrast, impulse control and cognitive capabilities like planning and response inhibition follow a linear pattern, increasing gradually from age 10 onward and not reaching adult levels until the early to mid-20s. Brain imaging studies consistently show that adolescents recruit cognitive control circuitry less efficiently than adults, even when performing tasks equally well.
The developmental gap between these systems is largest in mid-adolescence—precisely when risk-taking behavior peaks across virtually all measures, including experimentation with alcohol and drugs, unprotected sexual activity, violent and nonviolent crime, and reckless driving.
The Peer Effect: Why Everything Changes in Groups
Perhaps the most striking application of Steinberg's dual systems model concerns peer influence. It's well established that adolescents are more likely than children or adults to take risks in the presence of peers. Crime statistics reveal that adolescents typically commit delinquent acts in peer groups, whereas adults more frequently offend alone. But the neuroscience explains why.
Building on experimental work showing age differences in the degree to which peer presence evokes risky behavior, Steinberg's lab brought peer context into the brain scanner. Using an event-related fMRI design, they examined age differences in neural activation at the moment of decision-making in risk-taking tasks, comparing performance when peers were observing versus when participants were alone.
The findings were dramatic. Among adolescents more than adults, the presence of peers "primes" a reward-sensitive motivational state that increases the subjective value of immediately available rewards. When adolescents know their peers are watching, their brain's reward circuitry—ventral striatum and medial prefrontal cortex—is activated more strongly.
In other words, peers don't primarily influence adolescent decision-making by affecting their reasoning or changing what they think—they affect the reward value of risky choices.
The research also shows that the presence of peers leads adolescents to more steeply discount delayed rewards, increasing their preference for immediate but smaller rewards over larger delayed ones. This provides further evidence that the impact of peers on risky decision-making is mediated specifically by their effects on reward processing rather than cognitive control.
Beyond Risk: The Social Brain in Adolescence
Research shows that adolescents are highly responsive to the social rewards afforded by positive peer evaluation, and these social rewards activate the same brain regions as non-social rewards like money. The heightened sensitivity to social information isn't a superficial concern about popularity—it reflects fundamental reorganization of neural systems that support social cognition.
This helps explain why adolescents spend an increasing amount of time with peers during precisely the developmental period when peer influence on decision-making is strongest. It's not random timing—it's the result of neurodevelopmental changes that make social connection and peer relationships neurobiologically compelling.
As adolescents move through this period, they show continued gains in response inhibition, planned problem solving, impulse control, and future orientation. Additionally, adolescents develop greater capacity to resist peer influence as cognitive control systems strengthen.
Science Meets Policy
Steinberg's research has profoundly influenced how the legal system treats adolescents. He served as the lead scientist on the amicus curiae brief filed by the American Psychological Association in Roper v. Simmons, the landmark 2005 U.S. Supreme Court case that abolished the juvenile death penalty.
The Court's ruling relied significantly on the argument advanced by Steinberg and his colleagues that adolescents are fundamentally different from adults in ways demonstrated by scientific studies of brain and behavioral development. Subsequent cases—including those limiting life without parole sentences for juveniles—have drawn on the same neuroscientific foundation.
As Steinberg testified: "In many respects adolescents are just as smart as adults. But it is crucial to understand that brain systems responsible for logical reasoning and basic information processing mature earlier than systems responsible for self-regulation and the coordination of emotion and thinking."
The Plasticity Paradox: Risk and Opportunity
The same neurodevelopmental processes that increase vulnerability to risky behavior during adolescence also create unprecedented opportunity for positive growth. The adolescent brain's heightened plasticity means this period is crucial for developing skills and capacities that will last a lifetime.
Steinberg argues that adolescence is evolution's way of bringing the capacity of our large, complex brains to fruition. Brain developments during adolescence drive growth toward independence via more complex reasoning skills, increased importance of social affiliations outside the family, and an urge to experiment and explore boundaries. In the context of still incomplete inhibitory systems, a heightened sensitivity to rewards can mean risk-taking in some domains. But the continued plasticity of the brain can also mean creativity, openness to novel solutions, and rapid skill acquisition in areas adolescents find meaningful.
Practical Applications: From Science to Support
Understanding the neuroscience of adolescence cam fundamentally shift how we approach guidance, education, and intervention with teenagers and young adults.
The mismatch between early-maturing reward sensitivity and late-maturing cognitive control isn't a problem to solve—it's a developmental reality to navigate.
Since adolescents are particularly responsive to immediate rewards and peer influence, ensure that desired behaviors have visible social rewards and recognition.
Understanding that impulse control systems aren't fully mature doesn't mean accepting dangerous behavior. It means structuring environments to reduce opportunities for high-stakes risks while providing outlets for the sensation-seeking and novelty-seeking that characterize this developmental stage.
The adolescent brain's malleability creates a limited window for efficiently developing self-regulation, emotional control, and executive functioning skills.
An adolescent who makes excellent decisions alone may make terrible decisions with peers present. Design supervision and support with understanding that peer context fundamentally changes adolescent decision-making.
With cognitive control systems developing into the mid-20s, young adults in their early twenties still benefit from scaffolding and support, even as they take on adult responsibilities.
Adolescents are exquisitely sensitive to social evaluation and peer relationships. It can be helpful to frame desired behaviors in terms of social contribution, peer respect, and meaningful connection rather than relying solely on adult approval or distant consequences.
Understanding Changes Everything
The teenage years aren't about holding on tight or letting go completely—they're about gradually transferring responsibility and decision-making while maintaining connection and providing appropriate structure. Understanding that your teenager's brain is undergoing dramatic reorganization helps interpret behavior that might otherwise seem willfully difficult or deliberately defiant.
A 15-year-old who makes an impulsive, risky decision in the presence of friends isn't rejecting your values or ignoring your guidance. Their brain's reward system is being activated more strongly than it will be at any other point in their life, while their capacity to regulate that activation is still developing.
Parents should maintain high expectations while recognizing that adolescents need more support meeting those expectations than their cognitive abilities might suggest. They can reason like adults in calm, reflective contexts, but they're still developing the capacity to apply that reasoning in emotionally charged, time-pressured, or socially salient situations.
The Opportunity of Adolescence
Steinberg's research delivers a message that's simultaneously cautionary and optimistic. Yes, adolescence is a period of heightened vulnerability to risky behavior, peer influence, and poor decision-making in certain contexts. But it's also a period of unprecedented opportunity for growth, learning, and positive development.
The brain changes characteristic of adolescence create both the challenges we observe and the opportunities we should seize:
The same heightened reward sensitivity that can lead to risky behavior also fuels motivation, passion, and engagement.
The same drive for peer connection that can result in dangerous conformity also supports the development of deep friendships, social skills, and collaborative capacity.
The plasticity that makes adolescent brains vulnerable also makes them extraordinarily capable of change, growth, and skill acquisition.
This is the age of opportunity—if we have the wisdom to recognize it and the commitment to invest in it.
A Helpful Resource
At YPM, our team has extensive experience successfully guiding adolescents, young adults, and their families through the modern landscape of emerging adulthood. Spanning four continents, our work has helped hundreds of teens and their families connect with professional youth mentors and expert clinicians who understand the neuroscience of adolescent development.
Our highly skilled mentors utilize developmentally appropriate approaches that work with—not against—the realities of the adolescent brain. We understand that the teenage years aren't just about surviving risk but about leveraging the extraordinary plasticity of this period to build capacities that will serve young people throughout their lives.
With our bespoke approach and discreet care, we can help your struggling loved one navigate adolescence with support that's grounded in cutting-edge neuroscience rather than outdated assumptions.
Connect with us today to learn more about how we can provide guidance informed by the science of adolescent brain development.
Key Studies and Works Cited
This article is based on the research and writings of Dr. Laurence Steinberg, Distinguished University Professor of Psychology and Neuroscience at Temple University and author of Age of Opportunity: Lessons From the New Science of Adolescence and You and Your Adolescent
Steinberg, L. (2008). A social neuroscience perspective on adolescent risk-taking. Developmental Review, 28(1), 78-106.
Steinberg, L. (2010). A dual systems model of adolescent risk-taking. Developmental Psychobiology, 52(3), 216-224.
Chein, J., Albert, D., O'Brien, L., Uckert, K., & Steinberg, L. (2011). Peers increase adolescent risk taking by enhancing activity in the brain's reward circuitry. Developmental Science, 14, F1-F10.
Shulman, E. P., Smith, A. R., Silva, K., Icenogle, G., Duell, N., Chein, J., & Steinberg, L. (2016). The dual systems model: Review, reappraisal, and reaffirmation. Developmental Cognitive Neuroscience, 17, 103-117.
Steinberg, L. (2014). Age of Opportunity: Lessons From the New Science of Adolescence. Boston: Houghton Mifflin Harcourt.