Morgan Winkworth
KSP 605

NCSS Standard IV/ Performance Expectation (d) apply concepts, methods, an theories about the study of human growth and development, such as physical endowment, learning, motivation, behavior, perception, and personality.

            Mood swings, recklessness, and risky behavior are all adolescent activities that were once attributed to “raging hormones.”  That is no longer the case.  Studies done in the last six years have produced information that suggests brain growth during this period may be the root cause of many behaviors and attitudes that are associated with adolescence (Crenson, 2000).  It is now known that the human brain is not fully matured at the age of puberty, as previously thought.  In fact, research has shown growth of both the temporal lobes and the frontal lobes of the human brain well into the mid to late teen years.  It has also been discovered that a significant period of brain growth, similar to the overproduction of gray matter during the first 18 months of life, occurs just before and during puberty (Giedd, Blumenthal & Jeffries, 1999).  This is significant, both to teens and teachers, for a number of reasons, which I will discuss later.

            It was once commonly accepted that the human brain reached developmental maturity at around 10-12 years old, or roughly the age of puberty.  Current research now shows that the frontal lobes as well as the temporal lobes continue to grow and develop beyond the onset of puberty, and well into the teen years (Meece, 2002).  The frontal lobes are the parts of the brain responsible for what neuroscientists call the “executive functions.”  These functions include judgment, self-control, emotional regulation, planning, goal and priority setting, organization and impulse inhibition (Crenson, 2000).  This sheds new light on the behavior of teenagers and gives at least some sort of rational explanation for otherwise irrational behavior. 

The temporal lobes, or the Amygdala, are the parts of the brain that are responsible for the development of language, and emotional control (Meece, 2002).  These parts are also developing beyond puberty, until the age of 16 and in same cases longer.  One series of MRI studies, done at Harvard’s McLean Hospital, scanned the brains of teenagers between 11 and 17 years old to observe the processes occurring in different parts of the brain when subjects were asked to identify the facial emotions conveyed in various pictures.  Older teens more accurately identified the pictures and their brains “exhibited a more progressive shift of activity from the amygdala to the frontal lobes (Baird, Gruber & Fein, 1999).”  Younger teens often misread the expressions and showed activity that occurred primarily in the amygdala without much used of the frontal lobes.  This shows that in teens the full potential of the frontal cortex’s ability to judge and reason is not yet fully developed (Baird, Gruber & Fein, 1999).

Another interesting, recent development is the discovery of a second stage of gray matter growth in the human brain.  Prior to this discovery, it was believed that gray matter was only produced in the mother’s womb and for the subsequent 18 months of a child’s development (Giedd, Blumenthal & Jeffries, 1999).  Gray matter is generally the thinking part of the brain comprised of a mass of neurons, and newly formed synapses.  When this growth occurs, new “hard-wiring” of the brain can take place.  Following the overproduction of gray matter, the brain undergoes a process called “pruning” where synapses that are not used wither away, and those that are used stay (Giedd, Blumenthal & Jeffries, 1999).  These findings now indicate that a significant period of growth, the gray matter period, occurs at a time in an adolescent’s life when they have more control over their own experiences and therefore the development of their own brain.  This has huge implications for students and teachers alike.

The knowledge of continued brain growth during adolescence is important for teachers to have.  It means that at a point in students’ lives when they are shaping important decision-making and critical thinking parts of their brains, we as teachers are their source of information.  We obviously don’t have access to students during the first 18 months of their lives but we do have access to them at this second “pruning” stage where the information we give them, and the way we have them use their brains will affect them at a neurological level for the rest of their lives.  This may be giving teachers a little too much credit for their influence over students but it can’t be denied that adolescent years are very influential years for students.  It has always been known, but now it can be scientifically proven.  We can’t keep students from maintaining and developing synapses that assist in playing video games or watching television but we can try to spark interest in learning and critical thinking that may help to develop the synapses that add to a well-rounded, intelligent mind.

Bibliography:

Baird AA, Gruber SA, Fein DA, et al (1999).  Functional magnetic resonance imaging of facial affect recognition in children and adolescents.  Journal of the American Academy of Child and Adolescent Psychiatry, 38(2):  195-9.

Crenson, Matt (2000, Dec. 31).  Brain changes, not hormones, explain many adolescent behaviors.  Associated Press.  Online @

http://www.s-t.com/daily/12-00/12-31-00/e05li127.htm  Accessed: 11/2/06.