Is There a Gene for Shyness?
But which genes are involved? One line of evidence leads to serotonin, which has numerous functions in the nervous system including an influence on mood, memory and learning. Irregularities in the expression or control of serotonin have been linked to depression, anxiety and a variety of other disorders. Drugs such as Prozac™ which affect serotonin are are now widely used in medicine.
In 1996, geneticist Dean Hamer of the National Institutes of Health and his colleagues reported that they had found an association between the serotonin transporter gene and neuroticism, a complex of behaviors that includes depression, low self-confidence, and shyness around strangers. Hamer reported in Science that adult volunteers who rated high on the scale of neuroticism tend to have a short version of the serotonin transporter promoter, a stretch of DNA that controls how much of the serotonin transporter gets made. Adults who ranked low in neuroticism tended to have a long version of the promoter.
Both the long and short copies of the gene are functioning, says Hamer. However, the short version appears to result in less of the serotonin transporter, and thus less serotonin activity. Hamer called it the "anxiety gene." Meanwhile, other studies suggest that another gene, DRD4, may also play a role in traits such as shyness and anxiety. The DRD4 gene codes for a protein that binds dopamine, another chemical messenger that has powerful effects in the brain. Again, the DRD4 gene comes in two forms: a long and a short version.
In a study reported in a recent issue of Molecular Psychiatry, behavioral scientist Judith Auerbach, of Ben-Gurion University, Beer Sheva, Israel, said that infants with short copies of the DRD4 gene and serotonin transporter promoter are less responsive to stimulation and show more distress during daily routines, compared to infants with different versions of these genes. Auerbach cautions that her findings do not define a gene or genes that predispose infants to future shyness. "That will only be clearer when the infants are older," says Auerbach, who is continuing to study the behavior of these infants as they grow. It is also interesting that a number of studies have linked the longer DRD4 gene to novelty-seeking behavior, just the opposite of being shy.
But which genes are involved? One line of evidence leads to serotonin, which has numerous functions in the nervous system including an influence on mood, memory and learning. Irregularities in the expression or control of serotonin have been linked to depression, anxiety and a variety of other disorders. Drugs such as Prozac™ which affect serotonin are are now widely used in medicine.
In 1996, geneticist Dean Hamer of the National Institutes of Health and his colleagues reported that they had found an association between the serotonin transporter gene and neuroticism, a complex of behaviors that includes depression, low self-confidence, and shyness around strangers. Hamer reported in Science that adult volunteers who rated high on the scale of neuroticism tend to have a short version of the serotonin transporter promoter, a stretch of DNA that controls how much of the serotonin transporter gets made. Adults who ranked low in neuroticism tended to have a long version of the promoter.
Both the long and short copies of the gene are functioning, says Hamer. However, the short version appears to result in less of the serotonin transporter, and thus less serotonin activity. Hamer called it the "anxiety gene." Meanwhile, other studies suggest that another gene, DRD4, may also play a role in traits such as shyness and anxiety. The DRD4 gene codes for a protein that binds dopamine, another chemical messenger that has powerful effects in the brain. Again, the DRD4 gene comes in two forms: a long and a short version.
In a study reported in a recent issue of Molecular Psychiatry, behavioral scientist Judith Auerbach, of Ben-Gurion University, Beer Sheva, Israel, said that infants with short copies of the DRD4 gene and serotonin transporter promoter are less responsive to stimulation and show more distress during daily routines, compared to infants with different versions of these genes. Auerbach cautions that her findings do not define a gene or genes that predispose infants to future shyness. "That will only be clearer when the infants are older," says Auerbach, who is continuing to study the behavior of these infants as they grow. It is also interesting that a number of studies have linked the longer DRD4 gene to novelty-seeking behavior, just the opposite of being shy.
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