Science / Medicine : Awfully Shy? Maybe It’s All in the Brain

There may be good reason why wallflowers stay clear of a crowd and prefer quiet jobs, say scientists who have found a possible link between shyness and levels of a key brain chemical.

The research, by scientists at Stanford University, is among a growing body of studies searching for chemical reasons to explain various personality traits.

In the latest work, they found low levels of the key brain chemical dopamine in 11 shy men they examined in what may be the first analysis to associate the neurochemical to a normal personality trait.

Dopamine is a substance that is crucial to normal neurological function, and abnormally low levels have been associated with Parkinson’s disease, schizophrenia and other disorders.

But the researchers cautioned that their findings do not suggest that shy people may have a greater predisposition to these conditions.

The research was led by Dr. Roy King and conducted at the Veterans Administration Medical Center in Palo Alto.

Dopamine-Activity Link

“I did go into the study with the intention of seeing if high levels of dopamine were associated with increased levels of social activity,” King said.

“In animal research, drugs which increase dopamine, like amphetamines and cocaine, tend to increase social activity in rodents,” he said. “So I reasoned that if such social activity as exploring holes is important to rodents and is increased when dopamine (levels) rose, then social activity was also important to primates, particularly humans.”

To King’s surprise, it was not high levels of dopamine that stuck out in his study but the markedly low levels in two-thirds of his test subjects--the people who he said expressed difficulty in social situations and who also had tested as being clinically shy.

King had administered personality tests to 16 men. The five who were found to be extroverted showed normal to slightly above normal levels of the chemical.

“Depressed people are very often shy, so now we have to extend this study to see if normals test the same way--that is, if we can get them to undergo all of the procedures,” King said.

His study supports recent work conducted at Harvard University by child psychologist Jerome Kagan, who found that some babies appear to be born shy. This was determined from the way they respond to strangers.