Studies link shyness with diseases

They’re the quiet ones in class. The ones that stare at
the ground and avoid eye contact. They shrink away from large
crowds, preferring the company of a few close friends.

In the world of introverted personality types, silence
reigns.

Scientists have documented the full consequences of this silence
““ introverted people are more likely to develop infectious
diseases, including AIDS.

Physicians in ancient Greece took note that those with a
“melancholic temperament” were more susceptible to
viral infections, including the flu.

Additionally, introverted people recover more slowly from these
illnesses than people with extroverted personality types, or those
that are more lively and outgoing.

No one knew why.

But now, UCLA scientists think they have made an important
discovery that may shed some light on this centuries-old
puzzle.

“We were interested in trying to understand the biological
mechanism that mediates psychological influences on infectious
vulnerability,” said Steve Cole, principal investigator and
assistant professor of hematology-oncology at the UCLA David Geffen
School of Medicine.

Cole’s team of scientists discovered that introverts had
higher levels of autonomic nervous system activity.

The ANS is responsible for regulating automatic processes such
as breathing, heart rate and blood pressure.

It was known that chemicals released from this system can
accelerate HIV replication in the test tube, Cole said.

“We wanted to find out whether a similar relationship held
in a clinical study,” Cole said.

The team studied a group of 54 men who were in the middle stages
of HIV, focusing on the effects of stress on viral replication.

Stress stimuli included beeping noises at unexpected times and
physical exercises such as deep breathing and standing from a
seated position.

The men studied were asked to solve math problems under time
constraints.

They found that men clinically diagnosed as being introverted
progressed toward AIDS faster than extroverted men.

Additionally, the introverted men did not respond as well to
AIDS treatment drugs.

“Shy, introverted people showed eight-folds higher levels
of virus in their blood,” Cole said.

The dramatically different levels of the virus were due to the
higher levels of ANS activity in introverted individuals, said
Cole.

Their findings show that the ways in which people respond to
different stress stimuli account for the differences in the
ANS.

The factors that determine whether an individual will be
introverted or extroverted seem to be a combination of nature and
nurture, said Marian Sigman, a UCLA professor of clinical
psychology.

“We think that children’s environment affects
development as well ““ not just that they’re born
(shy),” she said.

Should introverted individuals, then, be medically treated to
become more outgoing?

Not necessarily, Cole said.

Researchers are unsure whether a change in personality will
cause a different response to stress stimuli and also believe that
being introverted yields many positive things.

“(Introverts) are disproportionally responsible for our
greatest cultural achievements,” Cole said.

“Anything that requires depth and intensity, introverts
are better than extroverts,” he added.

His team is now in the process of testing drugs that can block
an introverted person’s ANS response to stress.