Do shyness and allergies go together?
Maybe, say researchers who have found that shy people are more likely to have hay fever.
"We think there is a small group of people who inherit a set of genes that predispose them to hay fever and shyness," said Jerome Kagan, a Harvard University psychology professor.
With three co-authors, Kagan surveyed 379 college students, asking them to report on their own shyness and their allergies. Their findings were published recently in the journal Psychosomatic Medicine.
Those students who reported a history of professionally diagnosed hay fever had significantly higher scores on the shyness index, Kagan and his co-authors found. Hay fever is an allergic reaction accompanied by sneezing and inflammation of the eyes and upper respiratory tract. It is caused mainly by exposure to grass and tree pollens.
Extremely shy adults seem to be more likely to have hay fever than outgoing individuals, said Kagan. But in the study, shy individuals were not more likely than outgoing people to report other types of allergies.
A link between shyness and hay fever might reflect differences in the receptors along the olfactory (smell) pathways or central nervous system circuits that regulate both mood and immune function, the authors said. In the past, other researchers have linked shyness with depression and allergies other than hay fever.
These recent findings are preliminary, Kagan emphasized, and may not be borne out in further research. Parents should not imply from the research that they should coax shy children out of their shells to alleviate allergies, Kagan added.
"If you have allergies, treat the allergies," agreed David S. King, a UCLA neuropsychology researcher and a co-author of the study. "If you are too shy, treat that."
But a Southern California allergist says the researchers might be looking at the link backwards.
"It's more likely the hay fever causes the shyness, not vice-versa," said Dr. Robert Ziering, a Vista allergist and UC San Diego assistant clinical professor of pediatrics. "A child with allergies may have a constantly runny nose. He hears teachers and parents telling him to take care of it. And that kind of input can cause kids to retreat into a shell to avoid the correction."