http://news.yahoo.com/s/hsn/20101008/hl_hsn/doyourgenestiltyoutowardthrillseeking

Do your genes predispose you to thrill-seeking?

Scientists looking into this question have found a dozen gene mutations
associated with the urge to do exciting things.

This urge, called "sensation seeking" by researchers, has been linked to the
neurotransmitter dopamine, a chemical that carries messages in the brain. In
research that involved 635 people enrolled in a study on addiction, the
scientists looked at 273 genetic mutations -- involving a change in just one
letter of the DNA -- known to occur in eight genes with roles related to
dopamine