Why we suck at evaluating risk
Why do we think cars are safer than planes? The answer is, our brains have flawed processes of risk assessment
How much do you value your life? Is it infinite? No, it can't be because you engage in possibly fatal activities all the time. For instance, you go to work every day, at least you did before lockdown. Every time you step outside on the road, there is a 1 in 55,000 chance that you will be a victim of a road accident, and a 1 in 700,000 chance of getting struck by lightning (ok that is pretty unlikely). So why do you go outside?
This is called risk perception - the balance between positives and negatives. You decide that the positive - you going to work - outweighs the negative - the chance of you ending up in a morgue.
Let me ask you another question. What do you think is safer, driving a car or air travel?
Most people think cars are safer than planes. Just think of all the horrible plane crashes in the recent past. Malaysia Airlines flight 17, gunned down over Ukraine. Pakistan Airlines flight 8303 crashed in Karachi. 257 people died in plane crashes in 2019, as stated by BBC. That's a lot, right?
But, according to the National Highway Traffic Safety Administration (NHTSA), 38,800 people died from car accidents that year in the US alone. You may say this is because a lot more people drive cars. So, a better unit is death per billion passenger miles, which is 11.3 for cars, and a measly 0.07 for planes, as claimed by NHTSA and FAA, respectively. Ironically, the deadliest part of air travel is the commute to the airport.
So, why are our risk perceptions so wrong? Why do we think cars are safer than planes? The answer is, our brains have flawed processes of risk assessment. What we fear is fatal, and fatal is very different from what we perceive as fearful.
These are some of the rules of our risk evaluation system, taken from a study of attitudes towards risks by the University of Oregon and the University of Texas.
- The more people are exposed to a particular risk, the less the public will accept it. The risk tolerance for experimental medicine, which is given to a handful of people, is far higher than a vaccine, which is given to millions of people.
- We tend to accept higher risks for voluntary activities than involuntary ones. According to WHO, we are roughly 1,000 times more tolerant of voluntary risks than involuntary risks. For example, in society, 1 death in 1,000 due to alcohol is acceptable, but for household water, it is 1 in 1,000,000, as people can stop drinking, but cannot avoid using water.
- We tend to use disease as a sort of marker to measure risk. Perhaps we have grown accustomed to the fact that our deaths will be by disease, so doing anything riskier than disease is unnatural, because then we are more likely to die from that other activity than a disease.
- "People fear what they don't understand." This famous quote is very true in the context of risk. The more we know about something, the less perceived risk is. Take nuclear power, for example. It was first introduced to the world in the form of atom bombs dropped on Hiroshima and Nagasaki. In a 1970 survey, college students ranked thirty activities and technologies from most to least risky. Most of them ranked nuclear energy as the riskiest. In reality, it was about 20th on the list. Now that people know more about nuclear energy, perceived risk has gone down.
- The more exposure is given to a certain incident, the higher the perceived risk rises. A car accident doesn't get nearly as much attention as a plane crash. The Chernobyl disaster resulted in 4,000 deaths and has left drastic effects on generations to come, but this data is not presented side by side with the fact that 7 million people die due to air pollution each year.
- Our brains cannot comprehend risk through statistics. Paul Slovick, a researcher for the University of Oregon says, "Numbers are numbing to us. We don't value the 1000th death as much as the 1st one, though, in theory, they should be the same." This is why we tolerate natural disasters with little more concern than terrorist attacks. As Mother Teresa said, "If I look at the mass, I will never act. If I look at the one, I will."
These rules combine to create a simple fact - as a species, we are terrible at perceiving risk. Life itself is risky, as we cannot reasonably know how risky a certain activity is.
Still, our flawed risk perception system averages out through time to line up with real risk. The only time when this is worth considering is when our decisions affect risk for others. In this case, perception is very dangerous, as it can eclipse science and fact. The COVID-19 pandemic is the perfect example of that. You not wearing a mask can and will affect those around you. Numbers do not lie. They are as close we can get to the handwriting of God.