The Developing Brain:​Teen Edition Understanding the Teen Brain​

Picture from Edutopia.org website, Illustration by Leigh Wells

Understanding the Teen Brain
Adolescents have been characterized as reckless, irresponsible, fickle, moody, and difficult for thousands of years at least as far back as Aristotle. In modern times, we’ve blamed these qualities on hormones, but that is only a small part of the story. Hormones do, indeed, kick off puberty which kicks off adolescence, a period of brain development that extends from the onset of puberty (between 10 and 12 years usually) until the mid-20s (between 23 and 25 years usually). During this time, the adolescent brain is actually going a little haywire because it is frantically undergoing a reorganization process which lays the foundation for adulthood.

Adolescent brain scans reveal that reward systems mature well before inhibitory systems. That tends to confirm a major theory of teenage development.1

Between year 3 and year 10 of life, the brain is acquiring knowledge, physical and social skills, and preparing itself for the adolescent phase.  With the onset of puberty, hormones most notably trigger the physical changes associated with sexual development.  But they also trigger changes within the brain itself as it enters a second growth spurt.  Neurons and synapses are developing like crazy, and at the same time, parts of the brain are reconfiguring and strengthening their functions.  According to an article published in the Harvard Mental Health Letter,
Recent research has shown that human brain circuitry is not mature until the early 20s (some would add, “if ever”).  Among the last connections to be fully established are the links between the prefrontal cortex, seat of judgement and problem-solving, and limbic system, especially the amygdala.  These links are critical for emotional learning and high-level self-regulation.
These processes and changes are responsible for both the good and bad aspects of adolescence.  Yes, there are important good aspects. Robert Epstein, in an article at scientificamerican.com, writes
The truth is [teens] are extraordinarily competent, even if they do not normally express that competence.  Research I conducted with Dumas2 shows, for example, that teens are as competent or virtually competent as adults across a wide range of adult abilities.  And long-standing studies of intelligence, perceptual abilities and memory function show that teens are in many instances far superior to adults.
Epstein goes on to say
In the 1940s pioneering intelligence researchers J. C. Raven and David Wechsler, relying on radically different kinds of intelligence tests, each showed that raw scores on intelligence tests peak between ages 13 and 15 and decline after that throughout life.
Because so much “rewiring” is going on in the teen brain and because the links necessary for good judgment and decision-making are not fully developed, it is easy to see how adolescents can get themselves into trouble.  Recognizing that their brains are adult-like, but not yet capable of the judgement, control, and social intelligence that adults have, may help parents and family members weather the ups and downs their teenagers are experiencing.  More on this topic in the future!


Cheryl Stewart, MOTAL Board Member and Researcher
July 8, 2020
Notes
1 Prefrontal Cortex – “This brain region has been implicated in planning complex cognitive behavior, personality expression, decision making, moderating social behavior, and moderating certain aspects of speech and language.” (Wikipedia)
  Nucleus Accumbens – “The nucleus accumbens has a significant role in the cognitive processing of motivation, aversion, reward (i.e., incentive salience, pleasure, and positive reinforcement), and reinforcement learning (e.g., Pavlovian-instrumental transfer); hence, it has a significant role in addiction. … Part of the nucleus accumbens core is centrally involved in the induction of slow-wave sleep … and  plays a lesser role in processing fear (a form of aversion), impulsivity, and the placebo effect. It is involved in the encoding of new motor programs as well.” (Wikipedia)
2  ”And research I conducted with Diane Dumas as part of her dissertation research at the California School of Professional Psychology shows a positive correlation between the extent to which teens are infantilized and the extent to which they display signs of psychopathology.” (Epstein).
References
Epstein, Robert. The Myth of the Teen Brain. Scientificamerican.com. 1 Jun 2007. https://www.scientificamerican.com/article/the-myth-of-the-teen-brain-2007-06/ .  7 Jul 2020.
Merrill, Stephen. Decoding the Teenage Brain (in Three Charts). 31 Jan 2019. https://www.edutopia.org/article/decoding-teenage-brain-3-charts.  1 Jul 2020.
The Adolescent Brain; Beyond Raging Hormones.  Harvard Mental Health Letter. Jul 2005.  https://www.health.harvard.edu/mind-and-mood/the-adolescent-brain-beyond-raging-hormones.  1 Jul 2020.
Young, Karen.  The Adolescent Brain – What All Teens Need to Know. N.D. https://www.heysigmund.com/the-adolescent-brain-what-they-need-to-know/.