November 1999
The Miraculous Minds of Teens
The 1990s have been called "The Decade of the Brain." Advances in technology now allow us to actually watch the brain
thinking. What we are seeing is changing many of our beliefs about how the brain develops, when it develops, and what we
can do to optimize healthy development.
Why are girls more mature than boys?
With healthy nutrition and care, brain cells send messages at lightning speed. One of the reasons that toddlers toddle while
gymnasts soar is the different levels of development in these brain cells – called neurons. Human babies have the most
complex brains of all animals and also the longest period of dependency on caregivers. The rate of the development of
certain chemicals in these brain cells tracks the rate of emotional, cognitive, and behavioral maturity. Why are girls often
thought to be more mature than boys of the same age? A substance called myelin develops earlier among girls than boys!
Why do "smart" teens make "dumb" decisions?
Human brains are composed of areas that develop earlier or later in life. The center of the brain, called the limbic area,
develops early. It is the seat of emotions such as anger, fear and joy. The last area of the brain to develop is the
prefrontal cortex just behind the forehead. The prefrontal cortex handles decision-making and judgment, and it moderates
the raw emotions from the limbic area. We once believed that the prefrontal cortex was completely formed by age 10
or so. The new research shows that the prefrontal cortex continues developing into the early 20s. This helps explain
why teens sometimes seem so emotional – their prefrontal cortex has simply not developed fully enough to handle their
limbic emotions. It also helps us understand why "smart" teens (who get straight A's in school) sometimes make "dumb"
choices about their behavior.
What do drugs like Prozac® do for teens?
Neurotransmitters are natural chemicals that affect the brain's processing of information and feelings. New experiences,
especially those with an element of risk, cause a release of a chemical called dopamine in the brain. Teens seem to seek
the "rush" from this feel-good neurotransmitter more than adults, leading some of them to take chances such as shoplifting
or experimenting with drugs. Compared to adults, teens are more likely to experience low levels of another brain chemical
called serotonin, which is related to impulsive behavior. Teens with high levels of serotonin may become anxious or
obsessive about their appearance and body image. Drugs such as Prozac® are often effective at moderating the level
of neurotransmitters and helping teens regulate their emotions.
Some of the most important findings of the new brain research underscore the importance of nurturing care and healthy
environments in the early years. We have also learned, however, that the brain continues developing and organizing
itself throughout the teen years (and well beyond). These findings are helping explain the fascinating character of
teens – the mood swings, the inconsistent behavior, the risk-taking, and even sleep patterns!
Most preteens find it very difficult to grasp abstract ideas such as algebra and moral dilemmas such as abortion. They
are "concrete thinkers," meaning that they deal best with what they can see and touch right now. As the prefrontal
cortex develops during the teen years, most adolescents gain the ability for abstract thought, meaning they can plan
tasks with many steps, juggle several needs at once, and anticipate how their comments and actions will affect themselves
and others in the future. They move from rigid ideas of right and wrong to recognize that different decisions may be best
for different people and situations. When teens seem resistant to adult guidance, it may simply be because they are
unable to understand all the implications of their behavior. This does not mean that they are incapable – but rather
that adults need to be a source of information, support, and guidance.
The new brain research continues to provide new insights into teen development and reasons for behavior. It appears
that much of what we once thought of as the result of child-rearing ("nurture") has an important basis in genes and
physical development ("nature") as well. As we learn more about the miracles of adolescent brain development, we
will create new ways of helping teens understand the possible causes for their behavior. As parents and teachers,
perhaps we can also apply this knowledge to enhance our relationships with teens – and positive, nurturing relationships
are still the key to healthy brain development.
- References and further reading::
- "Inside the Teen Brain," Shannon Brownlee, US News and World Report, August 9, 1999.
- Magic Trees of the Mind, Marian Diamond and Janet Hopson, 1998
- States of Mind, Roberta Conlan, ed., 1999.
- The Scientist in the Crib, Alison Gopnik, Andrew Meltzoff and Patricia Kuhl, 1999.
This Ups and Downs was contributed by Dr. Don Bower, Associate Professor and Extension Specialist, Department
of Child and Family Development, College of Family and Consumer Sciences, The University of Georgia, Athens, Georgia.
Ups & Downs is edited by Stephen T. Russell, Ph.D., Assistant Youth Development Cooperative Extension
Specialist, University of California, Davis.
If you have any questions about this newsletter or would like more information
you may contact
Dr. Stephen T. Russell, 4-H
Youth Development Cooperative Extension Specialist