“To live life is to risk it. And when you feel the rush of air and catch the stink of hot breath in your face, you enter the secret order of those who have seen their own death close up. It makes us live that much more intensely.” Laurence Gonzales, “Deep Survival: Who Lives, Who Dies and Why.”

The front wheel of my bicycle shuddered suddenly after striking a large pebble, jarring me awake. Apparently, I’d dozed off for a few seconds after pedaling continuously for the past 22 hours. Now in pitch darkness, I was hurtling downhill on a loosely-packed country road with my odometer pushing past 35 mph. Looking up; my headlamp illuminated a doe and two trailing fawns sealing off the road.

Although risk is an inherent part of virtually every aspect of life, humans are surprisingly inept at risk assessment. We frequently worry more about low-possibility catastrophic events in remote settings, while ignoring higher-probability hazards in our immediate surroundings. Often, we succumb to the temptation of instant gratification, while ignoring longer term consequences. The illusion of control can provide a false sense of security and the belief that risks only apply to others. Recent research involving functional brain circuitry, hormones, neurotransmitters, genetic factors, and behavioral correlates has contributed to our understanding of differential risk tolerance in the human experience.

My wife had begged me to stay home; but, the allure of outdoor adventure as an interim escape from countless 55-hour work weeks in a windowless cubicle proved irresistible. I was determined to complete the series of continuous, timed bicycle rides of 125, 200, 250 and 375 miles through hilly terrain, in order to qualify for the Randonneurs’ Holy Grail – the 750-mile Paris-Brest-Paris ride in France.

 At a distance of only 50 feet from the middle fawn and closing fast, impact in one second was inevitable. The deer instantly froze in place. Instinctively, I jerked the front wheel to the right and then leaned hard left, gunning for the narrow gap between the fawns.

The minimum human reaction time to a visual stimulus is 200-250 milliseconds. Stress and perceived threat information relayed to the amygdala (paired almond-shaped structures at the base of the brain involved with emotional processing) lead to activation of the “fight or flight response” of the sympathetic nervous system and epinephrine (adrenaline) release, increasing heart rate, blood pressure, and muscle blood flow. This evolutionary response and additional rapid subcortical neural pathways, enable us to reflexively duck falling rocks and jump back from oncoming cars (or charging sabretooth cats), even before the “higher” brain areas fully realize what is occurring. Many prey animals and some humans momentarily freeze (hence the expression of being “scared stiff”) in dangerous circumstances, a reflex which undoubtedly saved the fawns’ lives, but would have doomed my own.

Although there is an abundant literature describing a “slowing down of time” and a flashing of the past before your eyes in life-threatening situations, I only glimpsed my future mangled body and mourning widow.

Under certain circumstances such as extreme peril, athletes in the “zone,” and some meditative states, enhanced mental processes can distort the temporal relation between external world events and their internal perception, appearing to momentarily slow down time. Near death, life review experiences are thought to originate from autobiographical memories, augmented by ordinary cognitive phenomena such as déjà vu. Surprisingly, events may be viewed simultaneously but rarely appear in chronological order. Deep emotions involving close family members and friends may also be experienced.

My wheels chattered fleetingly on the cinder road, fighting for traction, as I shot through the gap between the fawns. Then suddenly – miraculously – I was past the deer and upright! Momentary relief and gratitude were quickly swamped by feelings of power, invincibility, and exhilaration from an ensuing adrenaline rush. 

The reward/pleasure centers deep in the midbrain and basal ganglia light up on functional MRI studies with the anticipation of winning in risk takers. Food, sex, gambling, and addictive drugs elevate dopamine, a key neurotransmitter which reinforces enjoyable sensations and the desire to experience them again. Both dopamine and opiod pathways are involved in addictions. The “runner’s high” of endurance athletes is due to an intoxicating brew of serotonin, brain derived neurotrophic factor, and endogenous endorphins. Individuals prone to take risks have fewer dopamine-inhibiting receptors, leading to too much dopamine, which is also associated with impulsive behaviors in patients with Parkinson’s disease and normal subjects treated with dopamine agonists.

A significant component of risk-taking may be inherited. For example, the Daredevil DRD4 and D2 genes and the Warrior MAOA-L gene variant (associated with elevated dopamine levels) are more common in impulsive individuals. A recent international study of one-million people of European ancestry found 124 genetic variants linked with increased risk tolerance, involving two other neurotrnasmitters, glutamine and GABA. Although individual genes accounted for only minimal behavioral variance, cumulatively 60% of high thrill temperament is inherited and 40% is learned.

The remainder of the 375-mile ride was uneventful and I arrived at the final checkpoint with several hours to spare. Heedless of my recent near fatal collision, my euphoria remained unabated, as I eagerly anticipated the next ride. 

An intriguing aspect of thrill seekers is situational risk taking, depending upon the context and setting. The investment strategist conservatively managing your retirement portfolio during the week may be a weekend base jumper. Of particular interest to behavioral scientists, advertising executives, and outdoor adventurers is the “hot” emotional versus “cold” rational decision-making gap. For example, an exhausted mountaineer, having spent considerable time and effort to climb within close proximity of the Mount Everest summit, might press forward while risking death rather than prudently retreating, although the latter choice would be readily affirmed in a detached rational setting. 

“Adventure can be an ecstatic affirmation of a rich and positive existence,” according to Geoff Powter, clinical psychiatrist mountaineer and author of Strange and Dangerous Dreams. “The best adventurers are also aware of their place and time, thrilled by the beauty around them, appreciating where their journey fits into history and respecting what has come before,” but there is a “darkness of some kind – of ambition, of ego, of personal pain, of a need to please others,” which can carry an individual across “the line where ambition, passion, and dreams turn into something quite different.” 

Serial risk exposure can dampen an accurate assessment of associated dangers, evolving from novelty sensation seeking to frank risk addiction, and the need for increasingly more hazardous undertakings. A whitewater river guide shared an illustrative example during an interlude between rapids:

“I met this great guy who had some money and introduced me to skydiving. Unfortunately, the splendor and serenity quickly gave way to the incredible adrenaline buzz of the ground rushing toward me. I began to pull the ripcord later and later on successive jumps, until my beau pulled the plug on both my skydiving and our relationship.”

Theodore Roosevelt, no stranger to risk, averred, “Far better it is to dare mighty things, to win glorious triumphs, even though checkered by failure, than to take rank with those poor spirits who neither enjoy much nor suffer much, because they live in the gray twilight that knows not victory nor defeat.” Although fortune favors the bold (and the prepared), there is clearly a difference between reasonable and reckless risk. 

While recent scientific discoveries continue to unravel the complexities of risk in human decision making, the optimal approach to an outdoor experience was summarized decades ago by Colin Mortlock in The Adventure Alternative (1984): 

“To adventure in the natural environment is consciously to take up a challenge that will demand the best of our capabilities – physically, mentally and emotionally.

If you have given your genuine best, and either overcome the challenge or retreated with dignity through skill and experience… you have had a ‘peak experience’ with feelings almost indiscernible and beyond those common to normal or routine living. Ultimately life is about feelings, those that are concerned with the joy of living, rather than the anxieties of modern existence.”

Lawrence Swayne (lcsrad@hotmail.com) is a retired physician, frequent contributor to medical literature and Kaatskill Life, summer and winter member of the Catskill 3500 Club, and a lifelong outdoor enthusiast, writer and photographer, having completed a dozen double century bicycle rides and hundreds of miles of wilderness hiking and kayaking.