Heuristics take flight!

by Kevin Boehnke

Sitting in an airplane makes me feel more in touch with my own mortality. It’s hard not to feel vulnerable when I think about soaring through the air in a fragile metal tube at 600 miles per hour. Do you remember your last flight? The roaring engines, the seats shaking during take off and landing, and the unsettling feeling in your stomach as the plane drops towards the earth… During times like these, my mind turns to events like the unknown fate of Flight 370 on Malaysian Airlines or the tragic events of September 11, 2001. Frankly, the idea of being in a plane crash terrifies me, especially since I learned that there is nearly always at least one plane crash with over 100 fatalities per year, and over 100 smaller accidents besides. These thoughts often lead to the same self-rebuke, “Why did I put my life in someone else’s hands? Why didn’t I just drive?”


This repeated experience demonstrates my failure to overcome my innate experiential risk assessment processes. As I mentioned last time, humans use different heuristics to make snap judgments about every day decisions. Here are a few heuristics and biases that kick in when I’m flying:

As I’m about to board a plane, my thoughts start niggling at me: “Don’t you know it’s unsafe? Think about 9/11 and Flight 370!” This mental shortcut is the affect heuristic: my emotions (fear and anxiety) towards flying distort my perception of safety.

My fear and anxiety are also examples of confirmation bias: I’m ignoring information that doesn’t support my gut reaction about flying being unsafe. I feel a sense of unease when flying, perhaps because my brain cherry-picks  memories of flight disasters. My mind is processing information through the availability heuristic: by recalling memorable examples (like 9/11 or Flight 370), I feel like the probability of a similar event occurring is higher. The more I continue to think about plane crashes, my perception of how risky flying actually is becomes more distorted. This is the attentional bias: my perception of risk is being affected by my recurring thoughts about the dangers of flying.

Although I am consciously aware that my mind is doing this to me, my initial reaction is STILL fear and anxiety. Check out the figure below to see why my brain is working this way!

From How Fear Works by Julia Layton. In response to a potentially scary event (OMG A HUGE SPIDER!) or trigger (like flying), the brain causes an immediate fear reaction, sending signals through the “low road” to the amygdala. Simultaneously, a slower, analytic response (system 2) travels through the cortex and hippocampus, connecting the current event to past reactions and risk judgments.

The Consequences of Risk (mis)assessment

We know that humans, even those of us who pretend to be rational, still have gut reactions that make us misjudge risk. So how does this affect society?

A psychologist named Gerd Gigerenzer examined US travel data before and after 9/11 to see how the terrorist attack affected travel behavior. He found that in the year following the 9/11 attacks, people flew less: the amount of miles traveled by plane dropped between 12-20% compared to the year before. During the same time period, people drove more (especially in a way that would compensate for plane travel): the amount of miles traveled in cars on interstate highways increased between 2.2-5.7%. Compared to the years before and the years after, he estimated that there were an extra 1,595 deaths from car accidents in the year following 9/11, more than 17 times the number of air travel deaths (83) in 2000 in the US.

While many of us may instinctively feel that driving is intrinsically safer than flying, in 2012 there were over 33,000 deaths  caused by car crashes in the US alone, compared to 475 global fatalities from plane crashes. As reported in the New York Times,

“In the last five years, the death risk for passengers in the United States has been one in 45 million flights, according to Arnold Barnett, a professor of statistics at M.I.T. In other words, flying has become so reliable that a traveler could fly every day for an average of 123,000 years before being in a fatal crash.” 

Clearly, people drive more often than they fly, which contributes to the higher number of deaths from car accidents. Even so, the risk of death by car is still far higher. In your lifetime, you have a 1 in 84 chance of dying in a car cash compared to a 1 in 5051 chance of dying in a plane crash.

Although it might be a little bit more dangerous if you’re in Russia

If humans were purely rational creatures, the anxiety caused by flying should be less than that caused by driving. Even though I’ve flown countless times, I can’t reason my way out of this initial reaction without conscious effort. So who should we blame? We’re bombarded by fear every time we turn on the news, so isn’t this the fault of the media?

Maybe. Media sensationalism certainly plays a part in getting people hyped up over minimal risks; after all, tragedy makes for good ratings. While 9/11 was tragic and the whereabouts of Flight 370 remain a crazy mystery, the probability of similar events occurring is astronomically low. However, these stories are covered in ways that influence our unconscious biases. After hearing about the victims, their daily lives, and their tragic loss, we feel that we know them. We empathize easily with individuals, but have trouble personalizing numbers and statistics. The tragedy of victims in highly publicized events makes us feel their individual pain in a deeply personal way. However, as I mentioned last time, the media is subject to the same biases as the rest of us.

It’s probably impossible to fully reason our way out of how we’re wired to think. However, it is possible to recognize our limitations and try not to act on them. While I may freak out about flying, l strive to recognize the irrationality of initial my reaction and force myself to calm down and think carefully. As individuals and as a society, maybe that’s the best we can do.

Slovic, Paul, et al. “Risk as analysis and risk as feelings: Some thoughts about affect, reason, risk, and rationality.” Risk analysis 24.2 (2004): 311-322. link

Small, Deborah A., George Loewenstein, and Paul Slovic. “Sympathy and callousness: The impact of deliberative thought on donations to identifiable and statistical victims.” Organizational Behavior and Human Decision Processes 102.2 (2007): 143-153. link

Gigerenzer, Gerd. “Out of the frying pan into the fire: Behavioral reactions to terrorist attacks.” Risk analysis 26.2 (2006): 347-351. link