Extreme sports, extreme risks — what's the motivation?

Why are some people excited by high-risk activities such as underwater cave diving, BASE jumping and heli-skiing, while others are just plain horrified? People who participate in extreme sports "want to lead an exciting, adventurous life," said Temple psychologist Frank Farley, who has studied "type T" (or thrill-seeking) personalities for decades. "These thrill-seekers thrive on the uncertainty associated with activities that most people would consider scary."
Feb. 23, 2011 | CNN