Fear Junkies

Worry. Danger. Risk.

That's what we hear about all the time, as well as all the safety measures we need to put in place to protect us, but think about it. If you avoid all risk, you end up doing nothing.

Professional BASE jumper Jeb Corliss doesn't avoid risk. He's made more than 1,000 jumps in his career, parachuting off bridges, cliffs and buildings, including the world's second-tallest building, the Petronas Towers in Kuala Lumpur, Malaysia.

Controlling Your Fear

Corliss said, "For me, it's worth taking a risk to push things forward. As scared as you would be standing on the edge of a 1,000-foot building and jumping off it is exactly how scared I am. The only difference between the two of us is that I have learned how to control that fear."

And so have others, says Temple University psychologist Frank Farley.

"These people want to live, you know. They want to live for another interesting day!" Farley said.

Farley has studied risk takers for more than 30 years, from the dumb risk takers whose exploits are all over YouTube.com, to professionals like race car drivers who do it more carefully.

Farley refers to these folks as T-types. The T stands for thrill. When I asked him why anyone would take any risks -- it seems better to be safe -- he replied, "If we choke that off, we're dead."

Farley points out that America was founded by people who risked their lives to create our nation: "1776 was full of risk takers. If the British knew what they were doing, they would have executed all of them. Those are our founders."

Risk Takers by Nature

The immigrants who settled America literally risked their lives crossing the ocean to come here. These are our ancestors. It's as if we're hard-wired to be risk takers.

Think about the explorers Lewis and Clark. They traveled nearly 4,000 miles without a map.

Consider the Wright brothers: Every time they flew, they took their lives in their hands. In fact, Orville Wright once crashed during a test flight, killing his passenger. And Martin Luther King Jr., a huge risk taker, ended up paying for it with his life.

A Human Guinea Pig

Risk taking is exactly what Dr. Barry Marshall did, and he ended up winning a Nobel Prize for it.

For years, all the experts said that ulcers were caused by stress. They advised ulcer patients to eat a bland diet, to drink milk, and to take antacids for a lifetime.

Marshall had a hunch that ulcers were caused by bacteria found in the stomach. He shared his thoughts with gastric experts like Dr. Walter Peterson who thought Marshall was crazy. Peterson and others thought the bacteria Marshall was studying was harmless.

So to convince his colleagues, Marshall did something drastic. He infected himself by drinking a glass full of the bacteria and then recorded what happened.

"I started having stomach pains and vomiting attacks," Marshall told "20/20."

Finally, when his stomach started to show the beginnings of an ulcer, his wife made him take antibiotics. Marshall was cured and he went on to cure millions of others.

Marshall read us an excerpt from a letter he received from a patient.

"Dear Dr. Marshall, thank you, thank you, thank you, thank you one thousand times. I have boundless energy, eat popcorn with butter, pizza, peanuts, have an occasional vodka collins."

So let's celebrate the risk takers.

The movie "Gizmo!" does that. It's a hilarious chronicle of the incredible number of people who tried to fly under their own power, failing again and again. But in 1977, an amateur cyclist named Bryan Allen finally succeeded in flying the Gossamer Condor. He had it up in the air for just more than seven minutes, powered by only muscle and a bicycle wheel.

Farley said, "I like to think of the fourth R: We got reading, 'riting, 'rithmetic and risk."

Dangerous Jobs

Some of you embrace danger every day in your jobs. We all know about the risks soldiers and firefighters take, but it may surprise you that these are not the most dangerous professions.

According to the Bureau of Labor Statistics, the most dangerous job -- when you calculate the death rate per 100,000 people -- is fishing!

The TV show Deadliest Catch vividly illustrates the peril fishermen confront.

Within the last month alone, six fishermen have died outside Boston. We spoke to some of the dead fishermen's colleagues in Massachusetts who told us, "The risks are not coming back someday. It just happened a couple of days ago, here out of Gloucester."

The second-deadliest profession: logging. Most loggers die when they're hit by falling trees, but many more get injured. Doug Handy, a logger based outside of Albany, N.Y., told us his partner of 17 years is now unable to work after a tree fell on him and crushed his leg.

Handy had a bad accident himself a few years ago. A chain saw cut his eyelid, requiring 40 stitches. Yet Handy would never change professions. He likes the thrill, he told us.

"Why guys drive stock cars, and you know, it's exciting, you know, you're on the edge."

Fear Junkies

The loggers, fishermen and firefighters all share something with the kids who take stupid risks. Researchers say risk takers' brains are just different. They have higher arousal thresholds. It takes more danger to make them feel scared.

If you're one of them, Farley says, you know who you are. "You like novelty, variety, intensity, change. You don't like too many rules." That goes along with what BASE jumper Corliss told us when he described what he felt right before jumping off the Eiffel Tower.

"It was one of the jumps that scared me so much that I felt like I was going to throw up. I was literally on the edge shaking, like my body was uncontrollably shaking."

But Corliss also told us that "fear is literally what keeps you in check, and what keeps you from getting killed." Logger Handy reiterated that point. He told us the day he isn't afraid on the job would be the day he got injured.

It might surprise you to learn that Corliss is a cautious driver. In fact, he told us he drives like a grandma.

"You know, I'm on my way to go do something that most people consider dangerous like skydiving, the average human thinks that that's just, 'Oh my God, that's just beyond danger,' you know? Yet, on my drive to the drop zone to do a skydive I see three car accidents that probably involve fatalities."

In December, three people died testing their limits on Mount Hood in Oregon. And it's not just the climbers who face risks, but also the rescuers. During a recent rescue search, a helicopter crashed.

Still, in spite of all the dangers, taking risks has never been more popular. Climbers are expected to continue to flock to America's tallest peaks this summer. It's almost as if, the safer we try to make life, the more people take on risk.

Corliss left us with this final thought: "The reality is what makes life exciting -- that there's risk. I mean, that's what makes it fun. If there was no risk; then what's the point? The idea is to push the human species forward. The idea is to evolve. The idea is to become something new."