Our brains have evolved mental shortcuts to help us negotiate the myriad decisions that confront us every day. Seemingly automatic, these instincts evolved from ancient times to save precious energy and effort. But if we’re not careful, these “heuristics” can distort our thinking in ways that are often invisible and sometimes deadly. Wray Herbert explores our built-in heuristics in his new book, On Second Thought: Outsmarting Your Mind’s Hard-Wired Habits, excerpted here.
On February 12, 1995, a party of three seasoned backcountry skiers set out for a day on the pristine slopes of Utah's Wasatch Mountain Range. Steve Carruthers, 37 years old, was the most experienced of the group, though they were all skilled skiers and mountaineers. Carruthers had skied these hills many times and was intimately familiar with the terrain. Their plan was to trek over the divide from Big Cottonwood Canyon to Porter Fork, the next canyon to the north.
Within three hours, Carruthers was dead. As the skiers headed across a shallow, treed expanse, they triggered an avalanche. More than a hundred metric tons of snow roared down the mountainside at 50 miles an hour, blanketing the slope and pinning Carruthers against an aspen. Another party heard the avalanche and rushed to the rescue, but by the time they dug Carruthers out, he was unconscious. He never regained awareness.
The other two skiers in Carruthers' group survived, but they faced some serious criticism back home. What were they thinking? This pass was well known as avalanche terrain, and February was considered high hazard season. The chatter in the tight-knit skiing community was that Carruthers had been reckless, that despite his experience he had ignored obvious signs of danger and tempted fate.
None of this rang true to Ian McCammon. He had known Carruthers for years, and the two had been climbing buddies at one time. Sure, Carruthers may have been a risk taker when he was younger, but he had matured. Just recently, while the two men were riding a local ski lift together, Carruthers had talked adoringly about his lovely wife, Nancy, and his four-year-old daughter, Lucia. His days of derring-do were over, he had told McCammon. It was time to settle down.
So what happened on that fateful afternoon? What skewed this experienced backcountry skier's judgment that he would put himself and his party in harm's way? Did he perish in an avoidable accident? Saddened and perplexed by his friend's death, McCammon determined to figure out what went wrong.
McCammon, an experienced backcountry skier in his own right and a wilderness instructor, he is also a scientist. He has a Ph.D. in mechanical engineering, and as a researcher at the University of Utah, he once worked on robotics and aerospace systems for NASA and the Department of Defense.He already knew snow science pretty well, so he began reading everything he could on the science of risk and decision-making. He ended up studying the details of more than 700 deadly avalanches that took place between 1972 and 2003, to see if he could find any commonalities that might explain his friend's untimely death.
With the rigor of an engineer, he systematically categorized all the avalanches according to several factors well known to backcountry skiers as risks: recent snowfall or windstorm, terrain features like cliffs and gullies, thawing and other signs of instability, and so forth. He computed an "exposure score" to rate the risk that preceded every accident.
Then he gathered as much information as he could on the ill-fated skiers themselves, all 1,355 of them: the makeup and dynamics of the skiing party, the expertise of the group leader as well as the others, plus anything that was known about the hours and minutes leading up to the fatal moment. Then he crunched the data.
His published results were intriguing. He found many patterns in the accidents, including several poor choices that should not have been made by experienced skiers. He concluded that these foolish decisions could be explained by several common thinking lapses, and he wrote up the work in a paper titled "Evidence of Heuristic Traps in Recreational Avalanche Accidents." The paper has become a staple of modern backcountry training and has no doubt saved many lives.