The Availability Bias
Which cause more human deaths, sharks or horses?
Most of the people would answer ‘sharks’ to the above question obviously, right? Now let’s examine the statistics. As per data of USA for 2000–2009, the deaths caused by sharks were 9 whereas those caused by horses were 215.
So what happens, why most people perceive that sharks are deadlier than horses. The answer to this notion is availability bias or availability heuristic.
What you’re hearing is an opinion, not a fact.
So what exactly went wrong in our perception
When people are asked about the frequency of any event, instances of that event are loaded from memory and if we are able to recall the event fluently, the event is judged as high in frequency.
As in the above question, death by shark gets more media coverage; we are more exposed to that kind of news hence the fluent access of such an example from the memory. Whereas death by horse rarely makes it to any public audience which is why we are not able to recollect any instance from our memories.
Let’s take a look at few more examples of Availability Bias
- Divorces and scandals among celebrities and politicians catch much more limelight. So one is more likely to exaggerate the frequency of divorces and scandals in celebrities than in the masses.
- A recent plane crash will dramatically increase your concerns about flying.
- You overestimate your percentage of contribution to anything, as you are fluently able to recall the examples where you contributed.
Availability Paradox
In the early 1990s, a group of psychologists led by Norbert Schwarz conducted an intriguing experiment.
They divided a group of people into two subgroups and gave them a task. The first group was given a task such as
First, list 6 instances where you behaved assertively
Next, evaluate how assertive you are.
The second group was given the same task but they had to list 12 instances of behaving assertively.
And the results were astounding, people who listed 12 instances of behaving assertively rated themselves as less assertive. The reason of such paradoxical results was that people who had to list more instances found it difficult to list the instances (as they have to search for more examples in their memories) hence they evaluated themselves as less assertive. So when we are not able to recollect the examples fluently, we tend to underestimate the frequency of that category/event.
A professor at UCLA found a genius way to exploit this paradox. At the end of his course, he asked his students to list down the improvements of the course and then rate the course. According to the paradox, students who listed more improvements ended up giving higher ratings to the course.
Availability vs Reality
As Daniel Kahneman writes in his book “Thinking, Fast and Slow”
The world in our heads is not a precise replica of reality; our expectation about the frequency of events are distorted by the prevalence and emotional intensity of the messages to which we are exposed.
Our brain is prone to making biases and blindly believing our intuitions which may lead to errors in decision making. There are lot of factors that will affect the availability bias.
The main source being media coverage, which majorly shapes our ideas and biases and can go both ways. Media shapes the ideas of public and public shapes the content of media, an editor cannot ignore the public’s demand on certain topics. In this vicious cycle, some unusual events attract fewer audiences and can be perceived less important than they really are.
Another factor that can affect the availability of an instance would be the detailing and the vividness of a story or experience. If you saw a bus accident by yourself that would result in a greater effect than if you heard it from someone else.
Availability Cascade
Sometimes the experts (lawmakers, regulators) also get affected by these biases thereby impacting the public policies made by them. This process of unintentionally allowing these biases into the policies is called an availability cascade.
An availability cascade is a chain of events that emerges from minor events media coverage leading to public panicking and large-scale government actions or reprioritization of actions.
The most appropriate example for this cascade would be Love Canal, where buried toxic waste was exposed during a rainy season leading to contamination of water and foul smell around the area. A resident of the community became agonized and angry. Then availability cascade folded and the story got more attention, ABC News even aired a program titled The Killing Ground, and empty baby-size coffins were paraded in front of the legislature. Wide level panic happened and the government provided a superfund and established a team called CERCLA to handle the situation creating huge expenses. Although, the opinions differ about the event and the claims about the actual damage have not been substantiated, the funds given to mitigate the issue could have been used somewhere else and would have saved many more lives, had it been prioritized properly. Kuran and Sunstein wrote up the Love Canal story almost as a pseudo-event, while on the other side of the debate, environmentalists still speak of the “Love Canal disaster.”
Another great example would be Alar scare of 1989. This began with few press stories of a chemical used to stimulate the growth of apples when consumed in huge dosages, which can cause cancer in mice. These stories frightened the public increasing media coverage cascading the effect. This event caused the apple industry major losses starting with just a minor story.
The Human tendency with small risks is either totally ignored or given too much weight-age, nothing in between.
In today’s world, a large amount of budget is allocated to fight and mitigate terrorist activities while the budget for research of cancer cure is less. The deaths caused by cancer are far more than the deaths caused by terrorist attacks. Just because events such as 9/11 bring gruesome images of deaths and disaster in mind, the availability cascade has its impacts on the public as well as on the authorities.
I am not saying that governments should stop providing funds to the agencies which mitigate and fight terrorism or should not listen to the public opinions but if had it not been an effect of availability cascade, the action prioritisation would have been much better.
We can avoid falling prey to this bias by looking at the negative cases as well such as, how many not been killed by sharks? or how many have not been murdered?
Conclusion
In the end, I just want to say that, the human brain is prone to these biases and carefully understanding this bias will lead to better analysis of the situation.
Statistic over intuition will lead to better decision making, both for public and the lawmakers.
References
- “Thinking, Fast and Slow” by Daniel Kahneman
- Example references from https://www.youtube.com/watch?v=2_wkv1Gx2vM