There were 130 shark attacks in 2018. Did you know that? Do you care? You tell yourself you do. But you don’t. You care about the blood over the surfboard, the leg hanging by threads of muscle tissue, the rescue helicopter overhead and the heartwarming 60 minutes story of an attack victim and his mission of returning to surfing. You don’t care about statistics.
Shark attacks save lives. Not because sharks are clever. Though they do get lucky sometimes and bite a man’s undiagnosed-cancer ridden leg. The reason shark attacks save lives is because we’re stupid.
Introducing the Cognitive Biases
There are several of cognitive biases at play from the time you hear the story of a shark attack, to the time you decide whether you will swim at the beach. Here’s a brief description of each before I go into how they interact to form a Lollapalooza.
- Retrievability bias: When something is easier to recall, we overestimate its likelihood of occurring. For example, narratives are always easier to recall than facts. Thus, when we make decisions, we are more likely to value narrative evidence over straight, dry facts. This also applies to recency of news. Recent news is easier to recall, so you will put a higher probability on such news occurring again in the future.
- Von Restorff effect: You are more likely to remember what’s different than homogenous. People swim all the time. No one remembers the beach goer who paddled out, threw a ball with friends then swam back to shore. Everyone remembers the person who got attacked by a shark.
- Vivid Evidence: The more vivid a story or piece of evidence is, the more likely we are to believe it and remember it.
- Insensitivity to base rates: Actual probabilities of being attacked by a shark are thrown away in favour of stories and vivid evidence.
- Similarity bias: If we or our situation is similar to another person’s situation, we are more likely to be affected by what they say or do.
How Do the Biases Interact?
The news builds a vivid picture for you. The bloody, bitten surfboard, the face of agony, the angry looking Great White. It triggers an emotional response from within you, deep in your evolutionary roots, the part of you that keeps you alive.
You don’t see the news of the people who swam happily all day. The kids who built sand castles after being held above waves by their mother or father, splashing in the water on occasion. You have nothing to rebase the vivid shark attack story against. Nothing matches the vividness of a shark attack image.
You are given the statistics of shark attacks, but these statistics do not hit the same evolutionary root the story does. It hits our recently developed rational faculty. Our rationality is not developed enough to overcome the emotional default. You are more scared of sharks having seen the story.
The day you were planning to go to the beach was three days after you heard the news of the shark attack. Now you are reconsidering. When you think of the beach and the ocean, immediately you retrieve images of the shark attack. This retrieval then strengthens the neural pathway to that memory, making it more likely you recall it when thinking of the beach again. The loop of retrievability bias.
The victim of the attack was someone of your sex and within 3 years of your age. This person is like you. You feel the emotion even more intensely after learning this. There is no reason to fear sharks more after this fact. Sharks do not target demographics. Our minds, however, do not handle probability intuitively at all.
Ultimately you feel it’s best not to go the beach for now. Maybe you know it’s because of the recent shark attack, or maybe you constructed another story for yourself. Either way, whatever you think the reason of your decision may be, the fact is, you will not be swimming. A natural consequence is: You will not drown.
In Australia in 2018 there was one shark attack fatality. There were 249 drownings, 19% from the beach and 16% in an ocean or harbour. Clearly you should be more afraid of drowning than sharks.
The Drive to Fly
Air travel feels dangerous. Hijackings, exploding wings, people being sucked out of the open door is Hollywood cliché by this point. This is a film though, we can differentiate between fact and fiction. After hearing of a real-life high-jacking (see what I did there?), you may feel genuinely threatened by the thought of flying, or at least your subconscious will be a little more hesitant.
You drive more than you fly. You’re more likely to retrieve boring images of driving. Maybe you’ve witnessed or been in a car crash, but you’re less likely you recall that experience when attempting to summarise day-to-day driving.
Plane crashes are also more vivid than car crashes. More people die at once. There are bigger explosions, more destruction and more media attention.
You are in control when driving a car. You’re not in control when flying (unless of course you are a pilot). Because we believe we are better than average drivers we think we are safer when in control, despite the huge body of evidence supporting the contrary. This is the Lake Wobegon effect, or illusory superiority.
All of these come together in a Lollapalooza. After a recent plane crash or incident, people are more likely to drive. Driving is more dangerous than flying. Thus, after a plane crash more people die in car accidents.
Fly. It’s quicker and safer.
How to Stop Drownings Without Having Sharks Attack People
If we make drownings more news worthy, in particular recent ones at recent beaches, advertised (tastefully), with some bright language describing what happened, then weak swimmers will be more deterred from swimming. Those with the confidence to swim will still swim.
But this is not the best scenario either. Some of the more confident swimmers will actually be the worst swimmers. This is known as the Dunning-Kruger effect. The more you know, the less confident you are about what you know, and vice versa. To overcome this, the advertising could target these people, exploiting some similarity bias.
What to Do Now?
Our thoughts are our life. With these cognitive biases in mind, you probably won’t be much better at overcoming them than before. You can try. Try to think how you may be influenced in a decision by one of the described biases.
Maybe you will realise it doesn’t matter there was a recent shark attack. It does matter though. It matters for the opposite reason. There’s a (temporarily) satiated shark. The chances of being attacked have decreased. It’s a perfect time to swim.
In all seriousness, Daniel Kahneman himself believes attempting to overcome these biases is futile. Perhaps I am an exemplar of the Dunning Kruger effect, but I don’t think it is. Having these biases in mind means you can be more persuasive. If you can realise when they are influencing you and are able to walk away, then do so. Notice yourself being emotionally swayed towards a particular decision? Check the statistics. Take your time. Don’t be impulsive.
One Last Thing
Shark attacks don’t save lives. At least there has been no study to say so. It was an urban legend. Nonetheless, you will remember these biases. They are still real. You’ve remembered them because they were part of a vivid and compelling story. Once again a bias has fooled you. This time, the narrative bias.
