Why Some of Us Are Thrill-Seekers

Skydiving? Zip-lining? Volcano-boarding? Yes, say thrill-seekers, and there’s a reason.

Zorbing ball ride in Malaysia

Every adrenaline junkie knows the feeling: Heart pounding. Hands trembling. Blood racing. And then all of a sudden—flying. Plunging through the air, 18,000 feet above the earth, clinging to a parachute that could by all means fail. Hurtling 50 miles an hour down a 1,600-foot volcanic slope, on a "volcano board" popularized by young adventurers. Whooshing down white-water rapids on a flimsy raft. Or being strapped into a zero-gravity roller coaster and preparing to whirl upside down, again and again. Thrill-seekers crave that rush; they thrive on it.

"It's the excitement," says Frank Farley, a professor of educational psychology at Temple University in Philadelphia. "It makes things interesting, keeps you going. When this life is over, you want to be able to look back and say, 'I lived.' As Helen Keller once said, 'Life is a daring adventure, or it is nothing.'"

In the 1980s, Farley coined the term Type T personality to describe thrill-seekers, or those who crave variety, novelty, intensity, and risk. These are people who long for exciting, meaningful challenges. Some enjoy the physical sensations that come from being scared silly; others like the idea that they're pushing themselves to the extreme.

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At least to some degree, Type Ts are born that way, Farley says. Though researchers don't yet have all the answers, it's clear that biology plays a role. Neuro-chemicals like dopamine and testosterone appear to affect how inclined someone is to play it safe or live on the wild side, as does the amount of white matter in the brain.

Other factors are psychological and rooted in personality. Thrill-seekers tend to be creative folks who like to make up their own minds. "They're energetic and self-confident," Farley says. "And they feel in control of their fate. When they climb Mt. Everest, they figure they're going to come back. If someone tells them not to do it, that sounds like a rule, so away they go."

Margaret J. King, director of Cultural Studies and Analysis, a Philadelphia-based think-tank, studies human behavior and, more specifically, why people are drawn to roller coasters. These days, riders are in for dangling seats that throw them upside down and backwards in gravity-defying loops and twists. "You wouldn't think we would put ourselves in such a terrifying position," King says. "But terror gives us a chance to test ourselves, our own tolerance. We like the idea that we can get through it." Boarding a roller coaster makes us feel like "we're in imminent danger of dying," she explains. All the signals in our body tell us we're headed in a bad direction. "We can't get off. We can't stop the thing. And then when we do, there's a tremendous rush of adrenaline, of ecstasy and elation. That's why you see people bouncing off rides with their friends."

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Itching for a good thrill? Try one of these to get your heart pumping:

Indoor skydiving. Consider it a trial run before jumping out of a plane. At iFly facilities nationwide, you'll don a flight suit and helmet and go soaring inside a vertical wind tunnel. These are 14 feet in diameter and generate wind speeds of up to 160 miles per hour. Flights mimic the experience of free-fall skydiving without the parachute. If you're between ages 3 and 103, you can do it; cost typically ranges from $60 to $250.

Zip-lining. You don't need to be somewhere exotic to go zip-lining. Yes, it's most often associated with Costa Rica and Hawaii, but Michigan has zip-lines, too. No matter where you are, cables are strung between trees; participants wear a harness attached to a wheel that dangles from the line. In locales likes Costa Rica, you'll be mingling with monkeys 80 feet above ground, with a bird's-eye view of the jungle. At a mountain resort, you'll go whizzing over ski slopes or a canopy of trees. The fastest zip lines reach speeds of up to 100 miles an hour. It usually costs between $100 and $300.