The pursuit of a thrill can make us take crazy chances: bungee-jumping, say, or skydiving. And then there's paying for a prostitute when you're a public figure the whole world is watching. In all such cases, excitement is involved--so why does it seduce some of us while leaving others cold?
The answer may start with brain chemistry. In the 1990s, Israeli researchers identified what they thought of as a risk gene, a bit of behavioral coding that changes the reabsorption of the neurotransmitter dopamine, making it easier for some people to respond to stress or anxiety. The higher your threshold for...