Examining the Differences Between Teenage and Adult Brains

It is no doubt that teenagers and adults have significant differences in the way in which they think, behave and interact with one another. While there is a general presumption that this is due to hormones, one must look for a further explanation behind what we perceive as “stereotypical” teenage behavior.

The nervous system is the body’s decision and communication center. The central nervous system (CNS) is located in the brain alongside the spinal cord and the peripheral nervous system (PNS); these all work together to control regular aspects of a humans everyday life.

The prefrontal cortex is the section of the brain that essentially controls the rest of the brain. It is responsible for weighing outcomes, forming judgments and controls impulses and emotions It is associated with complex cognitive behavior, personality expression and moderating social behavior; It helps our understanding of one another. The prefrontal cortex communicates with other parts of the brain through connections called synapses. Scientists have found that teenagers experience growth in the synapses during adolescence. During puberty, the brain begins to get rid of the synapses it doesn’t need in order to make the other synapses much more efficient in communicating. This process of elimination starts at the back of the brain and moves forward, so the prefrontal cortex is the last part to be developed. Therefore, the prefrontal cortex of a teenage brain is significantly underdeveloped in comparison to an adult’s brain; it may not fully develop until your mid 20’s.

Furthermore, imaging studies have shown that most of the mental energy that teenagers use is located in the back of the brain, whereas adults do most of their processing in the frontal lobe. When teenagers attempt to use the frontal lobe, it seems that they exhaust it, requiring much more of the brain to complete the process than adults would. Because adults have already refined those communication synapses they can make decisions more quickly. The nucleus accumbens is an area of the teenage brain that is developed early on; therefore by adolescence it is fairly well developed – it is the area of the brain that seeks pleasure and reward. It is one of the greatest paradoxes of modern existence; humans grow far faster and stronger during their second decade of life, but their chances of dying increase rapidly at the same time – in the majority of cases, it all comes down to one bad decision.

So, what does it mean to have an underdeveloped prefrontal cortex in conjunction with a strong desire for reward? As it happens, this combination could explain a lot about stereotypical teenage behavior. Through the use of MRI scans, scientists have been able to look inside the brain, and it seems that changing voices, body hair and awkwardness around the opposite sex are not the only big thing occurring in the teenage years. The brain appears to undergo a growth spurt, which in effect causes the behavior we see in teenagers. Although hormones do play a significant role in explaining this behavior, studies prove that the brain functions itself may be behind much of this behavior.

Back to the prefrontal cortex – the functions of it include the ability to differentiate among conflicting thoughts, determine good and bad, future consequences of current activities and social “control” – the ability to suppress the urges that, if not suppressed, could lead to socially unacceptable outcomes. An adults prefrontal cortex rejects impulse thoughts to do things considered risky, as possible negative outcomes outweigh the positives. Teenagers do these things however because they’re seeking stimuli to satisfy their need for reward, whilst the prefrontal cortex can’t register all the risks these actions entail. But not being able to reign in thrill-seeking impulses can have devastating effects, such as self destructive addictions to alcohol and drugs.

In that developing prefrontal cortex, synapses are selected based on whether they’re used or not, so behaviors that shape the brain are more likely to be maintained if started at this age (e.g. smoking, drinking etc.). The brain is acting similarly to how a sponge does: it can ‘soak’ up new information and change it to make room for it, a concept known as plasticity.

To conclude, it would appear that while hormones do explain some forms of behavior e.g. higher levels of testosterone leading to ‘aggressive’ behavior (a behavior stereotypical of males), it seems that regardless of gender, teenagers undergo a slow development of the brain which leads to mental functioning that is evidently different to that of adults.