None of the 23 climbers made it to the summit by 1:00 pm, and only six climbers made it by 2:00 pm. Hall and Fischer, despite mentioning numerous times that climbers would be turned around if they could not make the summit by 1:00 pm or 2:00 pm at the very latest, did not turn the climbers around.

Hall and Fischer 'knew that individuals would find it difficult to turn around after coming so far and expending such an effort,' and past Everest guides even reported climbers laughing in their face when told that they would not be able to summit. The final push to the summit was incredibly dangerous and required perfect timing so auxiliary oxygen bottles would last and climbers would not get caught in darkness on their return to camp. Each climber had spent years training and preparing, and the final push to the summit was over 18 hours long, following weeks of difficulty acclimating and hiking to base camp. The sunk cost effect causes normally rational people to throw away common sense, allowing past investment decisions to effect their future choices, 'despite seeing consistently poor results,' writes Roberto, escalating what could have been non-situation.Īll three of these resources - time, money and effort - had been spent on Everest. People who are operating under the sunk-cost effect tend to double down on their commitment to a course of action in which they have invested considerable resources, like time, money or effort. If you want to be a truly powerful leader, take them time to learn more about your decision-making - you may even recognize a few of these biases in yourself.

I've condensed some common cognitive biases that Roberto found in action on Everest. These common and predictable cognitive biases impair judgement and the choices that people make and are especially disastrous in leaders.

Everest disaster book