Teens lack the cognitive controls needed for mature
behavior. According to recent research findings, the brain isn’t
fully mature until a person reaches about 25 years of age.
An article written by Time Magazine focuses on
recent research conducted by Dr. Jay Giedd, chief of brain imaging
in the child psychiatry branch at the National Institute of Mental
Health. Dr. Giedd has devoted the past 13 years of his career to
studying the brain growth and development in kids and teenagers. Dr.
Giedd has used his research to study certain behavior in teens.
Because of his research, what was once blamed on as being “raging
hormones” in teens is now being seen as the by-product of two
factors: an excess amount of hormones and a lack of the cognitive
controls needed for mature behavior. One surprising finding that
scientists have discovered is that the teenage brain grows very
little over the course of childhood. By the time a child is 6 years
old, the brain is 90% to 95% of its adult size. Babies are born
equipped with most of the neurons our brain will ever have. Human
achieve their maximum brain-cell density between the third and sixth
month of gestation. During the final months before birth, our brains
undergo a dramatic “pruning” in which unnecessary brain cells are
eliminated. Many neuroscientists now believe that autism is the
result of insufficient or abnormal prenatal “pruning”. What Dr.
Giedd’s long-term studies have found is that there is a second wave
of “pruning” that occurs later in childhood and that the final,
critical part of this second wave, affecting some of our highest
mental functions, occurs in the late teens. During adolescence,
there are fewer but faster connections in the brain. The brain
becomes a more efficient machine but the trade-off is that the brain
is also possibly losing some of its raw potential for learning and
its ability to recover from trauma. Right about the time the brain
switches from proliferating to “pruning”, the body comes under the
hormonal effects of puberty. Dr. Giedd’s best estimate for when the
brain is truly mature is 25 years of age. For parents, Dr. Giedd
says that it might be more useful to help teens make up for what
their brain still lacks by providing structure, organizing their
time, guiding them through tough decisions (even when they resist)
and applying plenty of patience and love.1
Makes Teens Tick?, Time
Magazine, May 2, 2004, pp. 1-8.