Brains under development

Did you know that there are 2 major developmental periods of the brain? The first occurs from before birth up to about age 3. Perhaps more surprisingly is that there is a second burst of brain developmental that begins in the pre-teen or “tween” years. At this point in time, a second wave of neuronal development occurs that can be observed in neuroimaging scans. Interestingly, the teen years that follow are important for maximizing the “specialization” and “efficiency” of brain processes. Somewhat ironically, making the brain more efficient involves actually pruning back some of the connections in the brain so that information is conducted and processed quickly and by fewer areas in the brain.

Because this is a time of so much important brain development, it is extremely important that teens know and understand that behaviours and activities that they engage in during these times can have long-lasting impacts. For instance, drug and alcohol use during these critical developmental periods may have more significant effects on the developing brain than we may have previously appreciated. If teens are provided this knowledge and education, they may choose to make decisions differently than if they are simply told not to use these substances “because they aren’t old enough” or some other vague reasons.

The development of the brain during the tween and teen years can also help to explain some of the seemingly bizarre and unpredictable behaviours of teens. While hormones have traditionally been blamed for a good chunk of teens’ sometimes “irrational” behaviour, it is possible that developmental brain processes play a bigger role.

“Executive Functioning” is a term used to describe the higher-order thinking skills such as: planning, problem-solving, organizing, inhibiting, and reasoning. These types of thinking skills are largely controlled by the very front part of the brain in an area called the “prefrontal cortex”. Interestingly, this part of the brain is the last part of the brain to develop in humans. Recent research suggests that development in these brain areas may not reach completion until about 25 years of age.

So, the next time you wonder about your teenagers ability to act “rationally”, consider that their brains are a “work in progress”. Although they may be able to demonstrate good judgment in some areas under some circumstances, it may not yet be a consistently developed skill. Therefore, this time is crucially important for teens to be able to have open, honest and frequent communication with a parent or another adult in order to help them to have the opportunity to develop these abilities with a fine balance of exploring their independence with adult guidance and support.

For more information on this topic, you may be interested to look at a resource created by the PBS program called Frontline. They have an excellent website with great resources and an interesting collection of videos that look at teen development issues in great detail.