But it now appears that a craving for exciting new experiences can be credited, in part at least, to a single gene. So say teams of researchers from Israel and the U.S. who announced independently last week that they have linked novelty seeking to a gene on chromosome 11. This marks the first time a normal personality trait has been firmly linked to a particular gene. In the two studies published in the current Nature Genetics, people filled out personality questionnaires and had blood taken for genetic analysis. The gene helps regulate dopamine, a chemical messenger in the brain that mediates pleasure and emotion.
Researchers have yet to figure out exactly how the longer gene affects behavior.
Researchers suspect that another four or five dopamine-related genes also contribute. Moreover, behavior ultimately depends as much on upbringing and opportunity as it does on innate temperament. Someone with the thrill-seeking gene might turn out to be a serial murderer, observes behavioral geneticist Irving Gottesman of the University of Virginia. And that has ethicists worried.