UNDER CONSTRUCTION

     Scientists and experts used to believe that the brain was finished growing at about age 10. However, recent studies show that there are parts of the brain that are not fully developed until mid-20s. This does not mean that teenagers are less intelligent, or that they have "half-a-brain". Basically, it means that the nerve cells connecting teenagers' frontal lobes with the rest of their brains are slow. This is due to the fact that teens don't have as much of the fatty coating known as myelin, or "white matter," that adults have in this area. The myelin is similar to the coating over an electrical wire. Just like the wire needs the coating to allow connections to flow without interruption, the nerves need myelin for the nerve signals to have a direct current. If the myelin is thin or mottled, this causes ineffective communication between one section of the brain to another. (National Institute of Mental Health)
    During childhood and adolescence, there are many changes occurring in the brain, including rapidly increasing connections between the brain cells and refinement (or pruning) of the brain pathways. The frontal lobe section of the brain is the part that deals with judgement, and decision-making, among other things. Scans of children's brain ranging in ages show that the decrease in gray matter were occurring in late adolescence. (See photo) 

The areas of the brain that are involved in more basic functions grow and mature first (e.g. controlling movement.) Sections of the brain that are responsible for more higher-level thinking/processing such as impulse control, problem solving, and planning ahead, are among the last to fully mature. (The Teen Brain)

     Finally, these differences in teen brains do not mean that teens don't know the difference between right and wrong, or that they should not be held responsible for their mistakes. The research sheds light on teenage behavior, helps parents and teachers understand, help and manage their teens. This information also gives teens insight to their own behavior.