Seeds of Shyness Are Sown at Birth and Lie Inside Genes, Scientists Find : Behavior: By observing how children act and how their bodies work, experts can select those who are predisposed to become timid adults.
Four-month-old David frowned warily at first when an orange and red plastic bear bounced on a string 2 feet from his blond head. Then slowly his face crumpled into a gargoyle scowl. He howled and arched his back and thrashed his tiny arms and legs.
Newness and uncertainty, the things that make life interesting for many, are clearly painful to David. Even though his time on Earth has hardly begun, a psychologist who watched his heart-rending reaction is quite certain what lies ahead:
David will probably grow up to be painfully shy, the kind of person who would rather have a root canal than strike up a conversation with a stranger.
“I’m afraid he will remain vulnerable to being anxious when things get out of his control,” said Jerome Kagan. “He won’t be an investment banker or a fighter pilot or anything else where there is likely to be risk and uncertainty. He’ll have close friends, but he won’t be the life of the party.”
In his lab at Harvard University, Kagan has videotaped how David and hundreds of other infants deal with funny noises, odd smells, weird toys and strangely dressed grown-ups. What he sees leads him and other psychologists to believe that the seeds of extreme shyness and caution are already sown at birth and probably lie within the genes.
Babies like David seem clearly unusual in many ways. They have easily excitable, revved up nervous systems. Even at 2 weeks of age, their hearts beat faster during sleep than the hearts of other babies. By 9 months, the pattern of brain waves inside their heads is distinctly different.
In new situations, their blood pressures are more likely to rise, their pupils to dilate and their vocal cords to tense. They tend to get hay fever. Often, they even look different: The very shy are more likely to have thin faces, slender builds and blue eyes.
Scientists believe that by observing how youngsters act and how their bodies work, they can pick out the ones who are predisposed--though not absolutely destined--to become shy and timid teen-agers and adults.
“We think we can go back and select the behavioral patterns that reflect the earliest temperamental origins of shyness,” said psychologist Nathan Fox of the University of Maryland. “We also think we can nail down the interaction between those temperamental patterns and brain activity.”
Kagan, the pioneer in this field, calls this inborn tendency “temperamental shyness.” Not all shy people have it. For instance, this category does not include youngsters who turn shy as they get older, usually after age 4, because of some disagreeable experience: They stutter; they are homely; they can’t play baseball. These children often fall quiet with strangers, but they are not unusually afraid of other things.
Temperamentally shy youngsters, however, are restrained and inhibited in all unfamiliar situations.
“These are children for whom the first reaction to every new food, every new stranger, every new place, every new smell is to push it away,” said Stella Chess, a child psychiatrist at New York University Medical Center. “If you give them a new food, it dribbles out the side of their mouths. If they come to a new place, they hide behind the person who brought them.”
Kagan estimates that 20% of middle-class white American children--the only ones he has studied--are born temperamentally shy.
At age 4 months, these babies fuss at almost any unexpected diversion. They arch their backs, flex their arms and legs and generally act worried at the sight of a gaily colored mobile or a whiff of alcohol on a cotton swab. They also sleep poorly at night, take short naps and are often irritable during their first eight or nine months.
In their second year of life, these youngsters are timid. They cling to their mothers around strangers, dislike noisy toys and are uneasy about anything out of the ordinary, such as an unfamiliar house or a new nursery school. If separated from their parents, they may be inconsolable.
As they grow older, they are often reserved and quiet with other children. Many are haunted by lingering fears of such bugaboos as being kidnaped or eaten by large animals.
However, the inborn tendency does not mean babies will unfailingly grow up to be withdrawn. Many learn to cope with their condition and even overcome it. Though they will never be gregarious backslappers, they will not be cringingly bashful, either. Kagan said that by age 8, about 10% of all children are still excessively introverted, and by age 20 only about 5% are this way.
“That doesn’t mean they have lost the temperamental quality,” said Kagan. “It just means that they’ve lost the external demeanor of being shy.”
Extreme shyness appears to run in families. But experts believe the trait is under the control of several genes, and inheritance patterns are extremely complicated. This is why bashful brothers can have gregarious sisters.
Psychologist Robert Plomin of Pennsylvania State University, who studies shyness in twins, said: “Studies suggest that shyness is the most heritable component of personality.”
Perhaps 50% of shyness is inherited, he estimates, while the rest might result from factors including childhood experiences and even the effects of maternal hormones while still in the womb.
Although precisely what these genes do is still a mystery, experts are looking for effects of their influence inside the brain that might account for shyness. Kagan bets the amygdala is at its root.
Among other things, this almond-size structure deep within the brain regulates the sympathetic nervous system, which causes perspiration, racing heart, dry mouth and all the other symptoms of fear.
“This is my hypothesis,” said Kagan. “What these kids inherit is a neurochemistry that makes the amygdala very excitable. That means that when an unfamiliar event occurs, it is ready to discharge, like a supersensitive thermostat in your house.”
Recent studies of brain waves offer another clue. Fox has found that at age 9 months, highly excitable babies show more activity in the front right parts of their brains than in the front left. Studies suggest that people with more activity on the left side tend to have sunny, outgoing dispositions, while those with more dominant right sides are likely to withdraw from novel situations.
Psychologists say that by spotting temperamental shyness early, they can help parents rear their children to overcome this innate tendency. The idea, they say, is for parents to gently push their youngsters to cope with their fears rather than to protect them from their anxieties.
“If you know a kid is shy, you respect it and go with it,” said Plomin. “At a birthday party, don’t drop the kid off at the curb and say, ‘Have a nice time.’ Send the child in with a friend. With simple tricks, parents can help the situation.”
But even if the bashful child grows to be a shy adult, that’s not so bad. Cautious, introverted people often excel in careers where they can work alone.
