You read about them all the time and perhaps shake your head a little.

Thrill seekers who challenge themselves with dangerous adventures such as climbing Mount Everest, jumping out of airplanes, and even scaling frozen waterfalls.

But what is it about these daredevils that make them so fearless?

In fact, experts say they're not fearless at all. It’s fear that keeps them so intrigued with such arduous journeys.

Glenn Sparks, Ph.D., of Purdue University explained that thrill seekers take part in such dangerous journeys because of the gratification they feel from mastering something that is so frightening.

“They might engage in this sort of thing because they crave the intense adrenaline rush or thrill that comes with doing it,” Sparks told Healthline.

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Death on Mount Everest

This fascination has come under a spotlight following the death of Maria Strydom while climbing Mount Everest last month.

Strydom, 34, and her husband Robert Gropel set out to reach the world’s highest summit together. However, Strydom stopped once she realized she was suffering with altitude sickness, and encouraged her husband to continue without her.

After reuniting with her husband, Strydom collapsed and died on their way down the mountain.

Why would anyone do such a thing knowing the potential risks that come with it?

“The risks are actually an essential part of it,” Sparks said. “Without any perceived risk, there can't be a feeling that any significant challenge has been conquered. As for sensation seekers, no risk — no adrenaline.”

Gropel told journalists he felt responsible for his wife’s death, but thrill seeking experts explained that determining how sick one is under the conditions on Everest is not a laboratory diagnosis. Strydom may have died anyway if Gropel had stayed with her and began the descent.

“It was a decision between two people who loved each other that outsiders might never comprehend,” said Frank Farley, Ph.D., professor at Temple University in Philadelphia and former president of the American Psychological Association.

“Life, and death, is like that,” said Farley.

Personality of a Thrill Seeker

Farley told Healthline there are various motives people have for doing something like climbing Everest, but one predisposing quality that is almost required is risk tolerance.

“Situations of high risk will always be encountered. Risk averse people will never be seen on Everest,” said Farley.

He explained that the height of Everest carries its own health risks such as oxygen and altitude sickness problems, and exhaustion. But for elite mountaineers, personality makeup is a big factor, with the Type-T thrill-seeking/risk-taking personality a prime candidate.

“T-Types are usually motivated by such factors as novelty, variety, challenge. They’re often innovative/inventive, optimistic with high self-confidence, believe they control their fate, and have high energy,” said Farley.

According to Farley, summiting Mount Everest is the gold standard for an elite climber and most elite climbers are risk takers.

“It is for many the jewel in the crown of climbing. Summiting Everest has got to be in an elite climber’s CV,” he said. “There are a lot of dead bodies on Everest. Despite the known number of deaths, they feel confident they can do it. And they also feel that summiting Everest is one of the most glorious moments and accomplishments in their life.”

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It’s in the Brain

Where does this thrill-seeking personality trait stem from?

“This high sensation seeking personality trait has genetic roots. It runs in families and appears to be caused by dopamine dysregulation,” Keith Johnsgard, Ph.D., clinical psychologist and author, told Healthline.

While the brain encompasses several distinct dopamine pathways, one pathway plays a significant role in reward-motivated behavior. For sensation seekers, engaging in life-threatening activities is gratifying.

“Lazy dopamine receptors located in the pleasure centers of the brain require far greater than normal stimulation to deliver the highs needed by those with those aberrant dopamine receptors — so they jump out of airplanes,” said Johnsgard.

Johnsgard added that the sensation seeking personality trait, which includes thrill and adventure seeking, grows in a steep manner in both boys and girls until it peaks in the late teens. After that, it declines in a constant way until age 60.

Johnsgard was a thrill-seeker himself and although he has never desired to climb Everest, he did climb a nearby Nepal peak above 20,000 feet without oxygen at age 60. He’s also done a dozen high exit parachute free falls near the Arctic Circle in Norway, as well as kayaked the Zambezi in Zimbabwe.

Johnsgard began a series of studies in the 1970’s of the personality makeup of men and women who were thrill seeking risk-takers. He tested hundreds of racecar drivers from novice to world-class and dozens of elite parachutists.

He explained that back then, racecar drivers and the like were widely labeled in the media as being stupid, crazy, or possessed with a death wish.

“My studies conclusively proved that they were just the opposite — above average in intelligence, remarkably emotionally stable, and non-neurotic. They are characterized by a unique personality profile, whether stunt pilots, downhill ski racers, or mountain climbers,” said Johnsgard.

Seeking New Heights

Joe Arvai, Ph.D., professor, thrill seeker, and director of Erb Institute for Global Sustainable Enterprise at the University of Michigan, told Healthline that he gets an emotional rush from such arduous journeys.

“I’m driven by new experiences that test my own limits,” said Arvai.

Arvai is an ice climber, motorcycle rider, and high elevation mountaineer. He has climbed in the Cascades, Canadian Rockies, Denali, and Eiger.

“I guess I would say, I’m a risk seeker, in addition to being a decision scientist,” he said.

Arvai said that his reaction to the prospect of an adventurous trip simply appeals to him on an emotional level.

“I like challenges, but I do my best to work within my limits. This means tempering my emotional attachment to these activities with some rational thinking during the lead-up to the trip, and while its happening,” said Arvai.

Arvai said that one warning sign individuals should be wary of when taking such a trek is overconfidence.

“This is the big one for me. This occurs primarily in younger men, but women may exhibit it also. The basis for this is what we call a motivational bias. That is, many people are motivated to think of themselves as ‘special’ — talented, skilled, etc.,” said Arvai.

He said that this is a motivational bias because we are motivated to think this way because “special” people tend to be highly valued in society.

“The reality is, sadly, most of us aren’t really that special,” Arvai added. “So, the trick is to recognize this, and work within our limits. Accidents can still happen, but we can dampen, not eliminate, the risks if we are prudent.”

Arvai stresses that explorers should train extensively when planning to climb Everest.

“Training, training, and more training. This entails physical training to withstand the stress on the body. It entails skills training to master the many complex moves that are needed on a long climb. It also entails training the mind to think clearly in the lead-up to, and importantly during, the activity, and mindfulness while the activity is actually happening.”

The experts said that climbers must plan carefully with a plan of ascent and descent, full understanding of weather projections, etc., and climb in the right season for Everest.

“In many people’s lives, to stand atop the highest peak would be a ‘transcendent thrill.’ But you need all the personal qualities and preparation I’ve noted. If not, don’t go. Try something less risky,” said Farley.

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