Heuristic Traps are a major factor in avalanche fatalities. Can we improve the way they are being taught?

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by Lindsay Mann & Rob Shaul



For the past five winter seasons, there has been an average of 27 avalanche fatalities in the U.S. each year.

According to Ethan Greene director of the Colorado Avalanche Information Center (CAIC) “humans trigger more than 90% of avalanche accidents, which suggests that even in the face of evidence indicating danger, powerful psychological forces can override rational judgment. ” He goes on to say that there are “human factors” which are clouding people’s decision-making skills.

In a 2004 seminal research paper, “Heuristic Traps in Recreational Avalanche Accidents: Evidence and Implications” avalanche researcher Ian McCammon reviewed 715 recreational accidents that occurred between 1972 and 2003 and identified 6 of these “human factors” which he described as “heuristic traps” that helped lead to avalanche deaths in the face of clear and obvious signs of avalanche danger.

McCammon concluded, “there is good evidence that many avalanche victims fell prey to one or more heuristic traps. But because this study is based on accident data, it can only demonstrate correlations between victims’ behavior and the presence of heuristic traps.”

The 6 heuristic traps common in avalanche incidents identified by McCammon are often taught by avalanche educations using the acronym “FACETS.”

  • F= familiarity – our past actions to guide our behavior in a familiar setting. You’ve skied this slope a dozen times and it’s never slid, so despite obvious avalanche warning signs, you ski it again this time.
  • A=Acceptance – tendency to engage in activities that we think will get us noticed or accepted by people we like or respect. You want to impress others in the group, and this causes you to overlook warning signs.
  • C=Consistency – an initial decision about something, subsequent decisions are much easier if we maintain consistency with previous decisions. I.e. …. we’re determined to ski this slope no matter what …..
  • E=Expert Halo – trusting an informal leader, who ends up making critical decisions for the ski group. He or she may not make the best decision.
  • T= First tracks. The heuristic this refers to is scarcity, tendency to value resources or opportunities in proportion to the chance that you may lose them. For backcountry skiers, this is called “powder fever” – wanting to ski untouched powder so bad skiers ignore obvious avalanche warning signs.
  • S= Social Facilitation presence of other people enhances risk-taking by a subject.   You see fresh tracks on the slope you want to ski, so even through avalanche danger is high, it must be safe, right?

McCammon defines heuristic traps as, “ when a rule of thumb gives us a grossly inaccurate perception of a hazard, we fall into what is known as a heuristic trap.”


Current Avalanche Education System

One McCammon’s most interesting findings was the link between increasing levels of avalanche education and the risk of being killed in an avalanche. We would think that increasing avalanche education would decrease the risk of being caught in an avalanche – but McCammon found the opposite – a higher level of avalanche education led to a greater chance of dying in an avalanche. This causes us to question how avalanche education is delivered, and it’s content.

There are many different organizations that are teaching avalanche education courses in the U.S. such as American Institute for Avalanche Research and Education (AAIRE), American Avalanche Institute (AAI), and the Alaska Avalanche School, among others. 

The American Avalanche Association, a public non-profit,  “promotes and supports professionalism and excellence in avalanche safety, education and research in the United States,“ and provides education guidelines, but it is up to each course provider to determine their curriculum.

Essentially there is no standardization as of now in the curriculum being taught in avalanche courses in the U.S. However, AAA, AAI, AAIRE and the National Avalanche School (NAS) have been working together to make changes in avalanche education.

In general, avalanche education cover three general areas: weather, snow science, and heuristics or human factors.

Anecdotally, in our experience taking and teaching avalanche courses, the curriculum for weather and snow science as it relates to avalanches is more structured than that of heuristics, and weather and snow science are given much greater emphasis in terms of course time. We’ve observed that the emphasis given to human factors/heuristics often is instructor dependent.

We hope to compare the amount of time spent teaching heuristic traps, human factors, and decision-making tools verse snow science, weather and other topics in the curriculum from the major US avalanche education providers.


Challenges to Teaching Avalanche Heuristics/“Human Factors”

We’ve identified several …

1) Terminology Needs Work
“Heuristics” is an academic term few are familiar with. “Human Factors” is too general to identify the avalanche-specific traps which have been identified. A more clear, attention-getting term to accurately describe this problem could help dramatically in bringing attention to it, improve awareness, but internally we’ve struggled to develop one. “Decision-Making” and “Better Communication” are both too general. Your ideas are appreciated.

2) 6 Heuristic Traps is too Many to Remember
Event with the “FACETS” acronym, six traps is too many to remember and specifically guard against. As part of our work, we hoped to apply the 80/20 rule to these traps … i.e. identify the 20% of these 6 traps which were responsible for 80% of the avalanche incidents, and focus on them. However, we were unable to do this. We used the American Avalanche Association’s database which listed all 30 of the avalanche fatalities in the U.S. during the 2015-16 Season.

The problem that we quickly ran into was the information surrounding each event varied.

What we found:

  • 12/30 fatalities involved skiers.
  • 10/30 fatalities involved snowmobilers.
  • 2/30 fatalities were women.
  • The average age was 36.5 years old.
  • 9/23 were not wearing avalanche transceivers, 1/23 had his avalanche transceiver turned on in his backpack.
  • The average age of people killed in avalanches last winter was 36.5, this excludes a 2-year-old child killed in a roof avalanche.

It is clear from these findings that avalanche centers do their best to investigate each avalanche fatality, however, due to uncontrollable factors, it is not always easy to get to the incident site in a timely manner.

It was also difficult to find information on the level of training of the avalanche victims. Due to the sensitivity of these incidents, there was not always information available on interviews with other members present in the party.

3) Teaching “Heuristics” in a classroom or field setting is difficult
Compared to heuristic traps, teaching weather and snow science factors in avalanches incidents are straightforward and solid. Teaching heuristics, in comparison, is much more fluid and “squishy.” Isolated case studies and general discussion seem to be used now, but to our knowledge, specific tabletop exercises, acted out scenarios, etc. have not been developed or tested. We suspect techniques to teach these traps have been developed and used in other fields, and disciplines – such as the military, or social sciences, and we intend to research these areas.

4) Incident Reports Aren’t Very Helpful
There are many reasons for this. One is that no one is required to report “near miss” incidents which could have been caused by heuristics. As well, poor decisions caused by heuristic traps in the face of clear avalanche danger can be embarrassing for those involved – further leading to not being reported.

Bruce Temper, former Director of the Utah Avalanche Center, talks about the “Culture of Shame” and the role that online forums and social media play. He says, “[Shaming] happens in online forums, social media, and in person, and the consensus amongst those not involved in the avalanche is usually something like this: ‘How could they have been so stupid to let this happen?’ As a result of that reaction, it actually hinders society’s ability to look openly at underlying forces that led to the accident in the first place.”

Link to the full article on the “Culture of Shame:” http://sportgevity.com/article/changing-culture-shame-0

Incidents which included avalanche deaths do get reported and written up by avalanche professionals, but it seems the reporting criteria is not standardized, especially when it comes to identifying the human factors/heuristics that could have led the accident.


Moving Forward

We need your help.

Heuristic traps are not unique to backcountry users. Doctors, pilots, military personnel deal with incidents caused by poor decision making frequently. A common tool used in these fields is checklists. Checklists are a way to help you make objective decisions when human factors can influence your judgment.

Speaking with a former Marine having objective debriefs is also a tool that is frequently used in the military as well, to help you to learn from any mistakes made and in hopes of identifying what could be done better in the future.

Reviewing case studies is another tool that we have discussed as a way to better teach and improve heuristics. Again, this is already being done not only in avalanche education but other fields to help identify ways to prevent accidents.

Specifically – we need assistance with…

  • Terminology. Can we develop a more accurate, and more memorable term for what is at play here?
  • Teaching Heuristics/Human Factors – Can we develop a teaching methodology beyond case study review and a general introduction to these concepts? Can we identify the 20% of the traps which cause 80% of the accidents and focus on them? Have you been exposed to or developed a way to effectively teach “human factors” in decision making?
  • Reporting – In terms of human factors, avalanche reporting is often incomplete and inconsistent. “Human Factors” affect many other mountain sports, and all tactical professions (military/LE/Fire Rescue). Have you come across a debriefing process or incident reporting method which honestly and effectively explores the possible human factors involved? Does your organization encourage honest reporting of poor decision making caused by these factors without embarrassment and incrimination?
  • Heuristic Checklist? – Already there exist avalanche decision-making checklist, thought tools and field cards which ask clear questions about slope angle, recent weather, avalanche signs, etc., (see AAIRE example below) but don’t address directly heuristics or human factors. Can one of these be created or can direct human factor challenge questions be incorporated into existing checklists? Have you seen this in your field? Can you share it?

If you can assist in with any of these or have any feedback or comments please email us at coach@mtntactical.com



  1. American Avalanche Association and Colorado Avalanche Forecasting Center.
  2. http://www.avalanche.org/accidents.phpKelley McMillan. “Skier’s Continue to Get Caught in Avalanches. Here’s Why they Overlook the Danger.” http://adventureblog.nationalgeographic.com/2016/01/21/more-skiers-are-getting-caught-in-avalanches-heres-why-they-ignore-the-dangers/ January 21, 2016.
  3. Ian McCammon. “Heuristic Traps in Recreational Avalanche Accidents: Evidence and Implications.” Avalanche News. No. 68. Spring 2004.
  4. Steweart-Patterson, Iain. “Avoiding the Illusion of Validity.”  http://www.americanavalancheassociation.org/wp-content/uploads/2016/06/TAR_34_April_2016.pdf
  5. Bruce Temper, “Changing the Culture of Shame.” http://sportgevity.com/article/changing-culture-shame-0
  6. Rob Coppolillo. “The Good Divide- the Upcoming ‘Pro-Rec’ Split in Avalanche Education. http://backcountryaccess.com/the-good-divide-the-upcoming-pro-rec-split-in-avalanche-education/ October 2015.



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