How to Explain the Disaster at Tenerife
On March 27, 1977 the deadliest disaster in aviation history took place on the Spanish island of Tenerife. In the midst of take off, going approximately 160 mph, KLM flight 4805 collided with Pan Am flight 1739 half way down the runway, killing 583 people. The KLM captain was Jacob Van Zanten, KLM’s chief flight instructor who had just returned from a six month safety course for commercial pilots. The subsequent investigation concluded that Van Zanten took off without clearance, thereby causing the crash. How could such a credited and experienced pilot make such a catastrophic mistake?
The events that preceded the accident were a recipe for disaster. A terrorist bomb had exploded at Gran Canaria International Airport, forcing several planes to divert to Tenerife, a small airport not used to handling large commercial jets. The control tower was understaffed, their English was weak, and a heavy fog had set it that prevented Van Zanten and his crew from seeing no more than 300 meters. All of these inputs contributed to Van Zanten making the fateful decision to takeoff without permission from the control tower.
The accident was also very preventable. Van Zanten could have doubled checked with the control tower or waited for the fog to lift. However, his emotions got the best of him and his lack of patience cost him his life, and the lives of others. An expert with years of experience makes a rookie mistake and turns out to be flat-out wrong. Why?
It turns out that there are a lot of answers to this question (mistakes and errors, especially those having to do with the aviation business, are hot topics in the popular psychologist literature), and I have seen the Tenerife disaster comes up in three books: The Invisible Gorilla (p. 20), Being Wrong (p. 303), and Sway (p. 10-24). While Invisible Gorilla and Being Wrong mention Tenerife anecdotally, Sway spends several pages explaining the anatomy of the disaster with three principles:
Loss aversion (our tendency to go to great lengths to avoid possible losses), value attribution (our inclination to imbue a person or thing with certain qualities based on initial perceived value), and the diagnosis bias (our blindness to all evidence that contradicts our initial assessment of a person or situation).
Sway’s explanations seem good enough, but it bothers me to see something like an airline disaster be explained by a few psychological principles. In isolation, each of the three principles make sense and have been empirically demonstrated a number of times. However, when it comes to something much more complex, like an airline disaster involving a huge number of inputs, I am skeptical of the explanatory power of a few psychological tendencies. In other words, aren’t there more forces at work than loss aversion, value attribution, and the diagnosis bias?
What about confirmation bias – the tendency to look for what confirms our beliefs and to ignore what contradicts our beliefs while disregarding the truth.You could say that in the minutes before van Zanten took off he only looked for indications of a safe take-off and ignored indications of a dangerous take-off.
Then there is cognitive dissonance – the tendency to hold on to an erroneous belief in the face of overwhelming contradictory evidence i.e., doomsdayers. You could also say that as van Zanten became more committed to taking off, it became increasingly difficult for him to change his mind.
Could there be more? Or are we missing something?
The point I am driving at here is similar to the one I made a few posts ago regarding Joshua Bell. That is, what does it mean for psychology to explain real-world phenomena? Put differently, what does it mean for something to be “explained” or “understood?” (and keep in mind van Zanten wouldn’t be able to help us nearly as much as you think, self-reports are almost never accurate.) I don’t know; but it is important that the popular psychology literature doesn’t get too gung-ho with their psychological explanations.
Kahneman, D., & Tversky, A. (1979). Prospect Theory: An Analysis of Decision under Risk Econometrica, 47 (2) DOI: 10.2307/1914185
JONES, E. (1967). The attribution of attitudes Journal of Experimental Social Psychology, 3 (1), 1-24 DOI: 10.1016/0022-1031(67)90034-0