Bias #140: Availability Bias; 3-minute read

Defined:

Availability Bias: A mental shortcut that leads people to assume that things they can more easily recall are more likely to occur. As a result, people tend to weigh their judgments toward more recent information.

Described:

What kills more people in a typical year, tornadoes or asthma? If you’re like most people, you probably said tornadoes. 

Here’s why: 

As you tried to answer the question, the first thing you did was try to recall examples of each. Instances of people dying in tornadoes come easily to mind because violent storms are eagerly covered by news media. But you may have struggled to remember examples of people dying from asthma, a quiet killer that attracts less attention.  

Next, you probably reasoned that because deaths by tornado were easier to recall, they were also more likely to occur. But, they’re not. Asthma kills about 100 times more people every year than tornadoes. 

As with so many other heuristics, availability bias occurs because our brain substitutes a different question—one that’s easier to answer—for the one it was asked. Instead of answering “Which takes more lives?” your brain answers the question: “Which can I more easily remember?” 

By leading people to misjudge probabilities, availability bias can cause them to take unnecessary risks. (It can even cause doctors to misdiagnose patients.)

When to use availability bias:

Whether people take preventative measures to avoid conditions like the flu or breast cancer depends in large part on how susceptible they believe they are. Therefore, it’s important to consider availability bias when planning behavior change interventions, so you can anticipate how people may judge—or misjudge—probabilities. If their perceived susceptibility is lower than their actual risk, you can use availability bias to bridge that gap.

How to use availability bias:

• Take advantage of current events. 

Popular news stories push their subject to the top of people’s minds, which you can use to your advantage. The best time to promote flu shots is after a prominent news story about a flu outbreak. New stories about the outbreak will cause people to believe they’re more likely to contract the flu. People who believe their risk of contracting the flu has increased will be more amenable to vaccinations. 

• Increase the odds. 

People often underestimate their risk of certain conditions. To increase their perceived probabilities, remind them of examples—the more vivid and personal, the better

The takeaway:

Availability bias describes how our minds try to predict probabilities with limited information. Make it work for you by using specific examples and trending stories to increase your audience’s perceived risk, and their likelihood of taking the recommended action.

And the next time you’re driving to the beach and hear a story on the radio about a shark attack, don’t hit the brakes. Car crashes kill significantly more people than sharks do.¹

About the author:

This Bias Brief was written by Greg Stielstra, the Senior Director of Behavioral Science at Lirio. Greg is a behavior change expert and published author with over 25 years of experience in marketing and engagement.

References:

1. Risk of Death – 18 Things More Likely to Kill You Than Sharks, International Shark Attack File, Florida Museum

Other readers viewed:

Omission Bias – Lirio Bias Brief

Ingroup/Outgroup Bias – Lirio Bias Brief

Temporal Landmark Effect – Lirio Bias Brief