Most parents shake their heads and blame hormones when their
teenager storms off and slams the door. But new research suggests that
such petulant behavior could actually be due to normal brain "remodeling"
that occurs during adolescence.
A recent study by researchers at San Diego State University, headed
by Robert McGivern, Ph.D., a professor of psychology, found that as
puberty kicks in, a child's ability to recognize other people's emotions
takes a downward turn.
The team tested the ability of 300 youths between the ages of 10
and 22 to judge emotions depicted in images and words. Subjects were
asked to say whether faces or words were happy or sad. The results showed
that reaction time largely depended on age, with speed dropping as kids
approached their teenage years.
Reaction times dropped starting at 11 years of age in girls, and 12
for boys--the approximate ages of puberty onset. The ability to identify
emotions for some dropped as much as 20 percent. The rise in reaction
time declined over the following couple of years and eventually
stabilized by age 15.
McGivern's study, published in a recent issue of Brain and
Cognition, showed that teens experience a sudden, natural increase in
nerve activity in the prefrontal cortex, the brain region that weighs
experience and perception to determine appropriate action. It also plays
a key role in controlling social behavior.
According to McGivern, teens have "noisier brains" due to the
increased nerve activity, although he doesn't rule out the role of
hormones. He describes it as a sort of temporary reorganization that may
make it difficult for adolescents to process information and read social
situations. This could be particularly tough, as social interactions are
often the dominant influence on teenage behavior.