BEHAVIOR: WHAT MAKES THEM DO IT

DO YOU GET A KICK OUT OF DANGEROUS sports like skydiving and whitewater rafting? Do you jump eagerly from job to job or even get a thrill from rearranging the furniture? If so, you are probably what psychologists call a "novelty seeker." The exact origins of personality types have eluded scientists for years. 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...