Why We Need to Rethink Our Conceptions of Adolescence

By Kristen Fay Poston

It’s no secret that adolescence today differs markedly from the period decades ago. Puberty begins earlier, and the adolescent years last longer, extending now into the early 20s (the transitional period that some scholars refer to as “emerging adulthood”).

One major area where we have seen a dramatic shift in our understanding of adolescent development is in brain development. Only within the last 25 years have scientists recognized that the brain is not a finished product by the end of childhood, nor is infancy the only critical period for brain development. Laurence Steinberg, a prominent scholar who has written significantly about adolescent development, recently published a book entitled “Age of Opportunity: Lessons from the New Science of Adolescence.”

Steinberg labels adolescence as the “new Zero to Three” because of the dramatic brain changes that characterize this period. Research demonstrates that the brain is more plastic during adolescence than in childhood or adulthood. Although evidence exists to support that brain plasticity and malleability continues well into the ninth and 10th decades of life, adolescence is the brain’s last period of especially heightened plasticity — for better and for worse.

The paradox of adolescence, then, is that this period both marks a time for potentially heightened susceptibility for increased risk-taking, mental health problems and transitional challenges, and for potentially enormous opportunity and positive growth. The same changes in the brain that increase adolescents’ propensity toward risk also allow for enhanced self-regulation and more controlled thinking.

Ultimately, whether adolescents’ developmental pathways are characterized by more or less unhealthy behaviors depends, in large part, on the quality of the experiences that we provide — whether in school, home, after school, or work-related contexts. Because of the explosive changes in the brain that are happening during adolescence, it presents a period ripe for targeted prevention and intervention efforts to increase the health and success of our youth and promote their early and sustained positive development.

The adolescent brain undergoes extensive maturation in three major regions that regulate experiences with reward and pleasure, how teenagers process social information and how youth exercise self-regulation and higher-order thinking abilities (e.g., planning, thinking ahead, weighing potential consequences). Science demonstrates where these changes are happening in the brain is just as important as when and what types of changes are happening.

During adolescence, the areas of the brain undergoing dramatic reorganization are the prefrontal cortex and the limbic system. The prefrontal cortex is described as the CEO of the brain — responsible for logical, rational and self-regulated behavior. The limbic system is the socio-emotional center, where social and emotional information are processed. The very different timetables for these developing areas create potential for heightened risk-taking and problem behaviors.

Steinberg describes brain development during the adolescence in three phases. During puberty, which marks the first phase, the limbic system becomes easily aroused and adolescents engage in more sensation-seeking behaviors, become more sensitive to peers’ evaluations and opinions of them and develop more dramatic emotional experiences (more highs and lows). During this time, adolescents’ emotions are running high, but their regulatory abilities and higher-order thinking skills have not yet fully caught up. Phase one is largely driven by pubertal hormones. Timing of this phase depends on his/her personal pubertal development and timeline.

In phase two, which begins around preadolescence and is generally completed by age 16 or 17, the prefrontal cortex becomes better organized, and advanced thinking abilities strengthen, which leads to better decision-making, planning and problem-solving. Although the elements for controlled and mature thinking are well-developed by the end of the phase two, these systems are not always used consistently. Fatigue, stress or emotional circumstances can interrupt a teen’s capacity to think logically and make mature decisions.

In Phase Three, which lasts until the mid-20s, interconnections between the limbic system and prefrontal cortex strengthen. Accordingly, then, adolescents’ mature, deliberate and controlled thinking becomes more dependable and less susceptible to outside influences.

Given all these changes and the varying timetables along which the socio-emotional centers and logical, rational domains of the adolescent brain develop, it is clear that peer pressure is not the driving factor in adolescents’ decision-making. A teen’s concerns over peer group status and peers’ evaluations reflect the changes in the social brain.

In addition, given their heightened sensitivity toward reward, diminished responses to loss and still underdeveloped self-regulatory behaviors, adolescents’ propensity to seek experiences where they can maximize rewards and novelty may sometimes lead them to engage in problematic behaviors (e.g., drug and alcohol use, risky sex). These behaviors reflect true developmental changes and offer opportunities for youth practitioners, educators and parents to redirect their efforts.

By focusing on some simple exercises and approaches in relationships with adolescents, adults can facilitate teenagers’ healthy and positive development. First, irrespective of the nature of one’s relationship with adolescents (teacher, parent, after-school provider, job supervisor), it is important to exercise consistency and warmth in these relationships. Warm, supportive relationships help foster better self-regulation in adolescents because they promote a sense of deeper security. In the context of warm, responsive relationships, adolescents develop greater confidence in their own abilities and emotions.

Second, within the contexts of these relationships, outlining clear expectations for adolescents is also critical. Explain the why of rules and decisions, and engage adolescents in a verbal give-and-take about these expectations. Provide opportunities for meaningful decision-making, choice and leadership that create a sense of ownership. Give over some control to adolescents as they become better able to manage tasks and self-regulate their behaviors. Encourage adolescents’ development of diverse skills that transcend knowledge-building competences. For example, emphasize creative thinking and problem-solving to foster skills that are often less present in traditional academic settings.

Where praise is in order, try to be explicit that the praise is linked to the effort adolescents are showing and not to the outcome or some innate quality (e.g., “You’ve worked really hard” versus “You are so smart!”).  For teachers and after-school providers, in particular, consider that social rewards carry valuable currency for teenagers, so balancing social and academic experiences in both school and out-of-school contexts is critical.

Finally, and arguably most importantly, recognize the potential for good and positive outcomes among adolescents is ever-present. Whether this potential is actualized depends not only on the teen but also on the critical people and contexts within his/her environment to help foster this positive potential.

Kristen Fay Poston, Ph.D., is a research scientist at the National Institute on Out-of-School Time at the Wellesley Centers for Women at Wellesley College and a visiting lecturer in the psychology department at Wellesley College.