Timothy Myers, M.Ed.'s  picture
Timothy Myers, M.Ed.
IMBES Visiting Fellow
Harvard University
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Understand Your Teen’s Brain

The teenage brain is as active as that of a 2-year-old, making new connections and, yes, mistakes, in order to grow

“You’re so mean—I hate you, Mom!”

Your daughter crosses her arms and rolls her eyes. How did restricting her to 25 texts a day turn you into the enemy?

Teen Arguing with Parent about Cell PhoneMost parents of a preteen or teenager can relate to the drama of adolescence. It seems that calm appeal to reason holds no sway when she is in the grip of adolescent angst. And while it is a fact that hormonal activity during this period of your child’s life can cause changes that affect her body, mood and interests, a great body of research shows that this is also a time of radical change in the structure and function of her brain, compounding her seeming overreaction. In other words, your teen is not just doing things she knows will drive her parents crazy. As Jay Giedd, a National Institute of Mental Health researcher studying brain development, notes in the 2008 Time magazine story “What Makes Teens Tick,” “There’s a debate over how much conscious control kids have. You can tell them to shape up or ship out, but making mistakes is part of how the brain optimally grows.”

Understanding the Teenage Brain

Just before puberty there’s a time of great growth in the brain’s prefrontal cortex, located in the front of the brain directly behind the forehead. (This period of growth is second only to the growth that occurs in the first few years of life.) During adolescence, the prefrontal cortex produces an exceptionally large number of synapses, or brain connections, that get pruned back, wired and rewired over the adolescent years, through practice and repetition. Researchers looking into teen brains theorize that this system offers the brain maximum flexibility to develop in a variety of ways. Like the brain of a baby, teen brains show a remarkable blooming of neuronal connections, allowing new avenues for acquiring abstract thinking, reasoning, attention and planning (what are referred to as executive function processes), as well as an eventual pruning back of unused synapses. In fact, brain development during this period is just as active as that of, say, a 2-year old, when new connections are being made. This flowering and pruning, like the spring bloom and autumn trimming in your garden, actually strengthens emerging adult connections in brain function.

Again, Giedd observes, “I think the exuberant growth during the pre-puberty years gives the brain enormous potential. The capacity to be skilled in many different areas is building up during those times… But the pruning-down phase is perhaps even more interesting, because our leading hypothesis for that is the ‘use it or lose it’ principle. Those cells and connections that are used will survive and flourish. Those cells and connections that are not used will wither and die.”

What’s Going On Here?

This is a time where new learning can flourish. Beginning around age 9 and throughout the teenage years, the brain shows remarkable plasticity—the ability to learn and make new connections. It’s a great window to encourage learning things that may be more difficult to pick up later in life, when new brain connections take greater effort.

Since the prefrontal cortex is home to abilities like reasoning, decision-making and judgment, you can help your child navigate her increasingly complex world by showing her how to plan and organize, by encouraging her to take increased responsibility for her actions and allowing her to assume the consequences for bad decisions.

The Sun’ll Come Out—Tomorrow

While it may seem this defiant daughter before you is too busy challenging you to listen to reason, she still needs you. Her brain is actually signaling this transition, as your teen, like her 2-year-old self, seeks to develop a separate identity apart from your authority. The good news is, you’ll win back her respect someday. Until then, you may have to wait for the storm to pass, reminding her that, as hard as it may seem to send only 25 texts per day, that is the limit.

LEArn More:

“Boost Your Teen’s Growing Brain,” more by Timothy Myers on how parents can help teens during this phase of “use it or lose it” brain growth

“Teen Reasoning: Not an Oxymoron”: how teens’ brain growth can help them improve critical-thinking skills, by Sandra Bond Chapman and Jacque Gamino

Related Reading:

“The Teenage Brain,” Dream magazine online, Children’s Hospital Boston

Inside the Teenage Brain, Frontline interview with Jay Giedd