PSYCHIATRISTS SAY people do it to satisfy a subconscious death wish. Some say they do it for its sense of high adventure, the feeling of accomplishment that comes from conquering mountains in the great outdoors; others say they do it just because it's there.

"I've heard all kinds of crazy theories as to why people climb," said Bob Norris, director of the Potomac Valley Climbing School and local guru of rock climbing. "It's a very personal and intense sport and the reasons behind it are very private. But I guess when all is said and done, you climb just because it's a lot of fun."

For the 39-year-old Norris, a 5-11, broad-shouldered man with shoulder-length, chestnut hair, a bushy brown moustache and two deep furrows etched in his cheeks, climbing has become a way of life.

He got into it in 1964 while on a post-college trip out west.

"I was walking around the base of the Teton mountains without the remotest idea that there was any sport called climbing," recalled Norris. "It occurred to me that somebody must have been to the top of those mountains, so I investigated and found a little climbing school."

For $10 he was taught a few knots, some climbing and rappelling, and he was hooked. Norris spent the next five years traveling across the United States 35 times, living out of a tent and working two months of the year to support his climbing habit.

He climbed the 3,000-foot monolith El Capitan in Yosemite, scaled peaks in the Canadian Rockies and the Cascades; he climbed in the snow, in the fading twilight and in the scalding heat of summer.

Norris returned to his home here in 1969 - "I got tired of going for months without sitting in a chair, sleeping in a bed or entering a building" - and began work as "a peseudo-rising young executive" in a big communications firm.

"After a while I looked around and decided the reasons I was doing that kind of work were not worth it," he said. "Monday is nothing to me. It's nice to have but I don't need a lot of material possessions."

So Norris quit his job and began working with a friend making things - "furniture, beds, anything." In 1971, he decided to convert his passion for climbing into a business and opened the Potomac Valley Climbing School.

"Frankly, I've often wondered why I started the school," he confessed, thoughtfully pulling on his thick brown mustache. "I guess I saw a need for it. There is no big more money but I can live off it and continue climbing."

Knowledge of the school spread by word of mouth through the climbing the grapevine and over the last six years he's introduced hundreds of prospective climbers to the techniques, safety measures and equipment used in rock climbing.

"I've never spent a dime on advertising because I don't feel climbing needs to be advertised," Norris said. "I prefer that people who come to me be motivated. I don't want people coming because they saw some ad. And over the years I've found that if people are interested in climbing they will investigate and they'll find me."

His basic beginner class is a one-day, eight-hour instruction that includes the fundamentals of knot-tying, rope management, dynamics. He charges $25 per person.

"Nobody can teach a person how to climb," Norris said. "What I can do in a class is give people sufficient background in what climbing is all about - equipment, some basic techniques and safety features - so that at the end of the day they have enough knowledge to go out and teach themselves to climb without ending up a statistic.

"At the end of a class I find that people either say, 'Okay, I have a good time, but these climbers are out of their minds and it's not for me,' or 'Hey, that was neat,' and go out, buy a rope, call a climbing club and start climbing."

Only about one person out of every 10 he teaches becomes a serious climber, Norris said.

He provides all the equipment for his beginners. A students is required to bring to class only sturdy shoes and clothing suitable for the weather. At the end of the class Norris tells his climbers that they can continue practice climbing by calling the mountaineering section of the Potomac Appalachian Trail Club.

After that an investment of about $150 is necessary for special rope, climbing shoes and a handful of other items.

Norris' climbing classes attract a wide variety of men and women, ranging in age from 12 (the minimum) up to mid-60s.

"I've taught an entire spectrum of people, and if I had to curve that spectrum I'd say it was skewed toward what you would call intellectuals," he said. "The sterotyped image of a climber is some kind of gorilla with big shoulders and huge hairy arms, but nothing is further from the truth.

"Climbing doesn't take brute strength. You need skill, coordination, a sense of awareness and a high degree of motivation."

A common misconception is that a climber throws up a rope and pulls himself up a mountain, but that's not the reason the rope is there.

In Norris' class climbers learn that the rope in top-rope climbing is for safety only. Climbers work in partners and loop a rope to an anchor at the top of the climb. One end is fastened to the climber's waist and the other is manipulated by his partner, a person on the ground called a belayer, who takes in slack as the climber begins an ascent, and braces the rope against his body if his partner falls.

"If you don't fall when you're practice climbing you're not learning," Norris said. "The rocks in practice areas are like a huge gymnasium - you constantly test your limits, try new climbs and prepare yourself to go out and climb harder rocks.

"People are capable of much more than they think they are," Norris grinned. "That's what I like about teaching. Someone will see a climb and say 'No way, man,' and I'll talk him up that climb, push him beyond what he thinks are his limits. And when he gets to the top it can be very exciting."

His credo is to avoid dangerous mistakes. "Seventy-five per cent of the accidents are a result of someone's knot coming untied," he tells his classes. "Climbing is exciting, and it's fun, but it's not worth getting killed over, so make a mental safety checklist."

But he is the fist to admit that the risks in climbing are part of its attraction.

"One reason I'm drawn to climbing is its decision-making process. Society has usurped the really profound decisions in our lives. Most day-to-day decisions, like whether to eat tuna fish or roast beef or buy a yellow or a red car, just aren't really all that important. But in the climbing world you're constantly making decisions that are damned important to you, and it gives your life meaning."