The slowdown in U.S. COVID-19 vaccination rates and increase in variants have given new urgency to motivate the remaining unvaccinated people to get their shots. The scientific consensus is clear: Only by immunizing the majority of the public can we hope to achieve herd immunity and contain the pandemic.
Research to test cognitive biases in vaccine hesitancy
I’m convinced that commercial behavioral science can point us to the right strategies. I lead a team focused on commercial applications of behavioral science. We often work with life sciences companies to improve patient care by identifying and incorporating key cognitive bias triggers into how they engage with customers. Vaccine hesitancy is a perfect illustration of how, even if we have all the information we need to make good health choices, cognitive biases can lead us astray and negatively impact personal and public health.
That’s why we worked with our colleagues who run the Vaccine Center of Excellence at ZS to design and field 20 behavioral science experiments across more than 620 adults in the U.S. and more than 4,400 adults globally. Each experiment was designed to test a separate cognitive bias to learn which tactics would actually change people from being hesitant to get a vaccine to being willing to receive one. Our study had two arms—one investigating COVID-19 vaccine hesitancy, and the other looking at adult vaccine hesitancy for proven vaccines, including shingles, human papilloma virus (HPV) and pneumococcal.
Cognitive biases are mental shortcuts people use to make thinking faster and cheaper for our brains to handle. These mental shortcuts work well to aid our cognition. But they become detrimental when we use them in the wrong settings, which can lead us to poor choices or unhealthy behaviors in ways we don’t recognize.
“It’s critical we embrace such insights now so we can stop doing what’s not helping and quickly pivot to powerful data-backed strategies that work.”
What is commercial behavioral science and how can you use it?
Commercial behavioral science is the application of behavioral science techniques and insights to the behaviors that are important to help companies and initiatives succeed. While many groups and organizations have tried to apply general best practices from behavioral and cognitive science, we have discovered that this approach is sorely lacking.
For example, many of the interventions we tested have been recommended by experts and are being used in vaccine persuasion work today. But in our tests, only seven interventions moved the needle on COVID-19 vaccine hesitancy. What’s more, just four interventions nudged people to change their minds about adult vaccines in general. And only two of the four adult vaccine interventions also were successful for COVID-19.
What our research revealed about vaccine hesitancy in U.S. adults
The goal of our research was to identify the discrete mental shortcuts that, when built into how we engage with vaccine-hesitant people, can nudge them in positive ways toward a willingness to get vaccinated. Between March 25 and April 15, 2021, we surveyed 620 U.S. adults, including at least 100 people of African American and Hispanic descent, who represented a mix of age, race, gender, geographies, employment statuses and income levels. We also were mindful to include respondents who represented the spectrum of vaccine-hesitant to anti-vaccine opinions.
We also surveyed more than 4,400 adults globally for this research and found that nearly all of the same nudges worked (and did not work) to encourage COVID-19 vaccination rates.
It’s not surprising that many of our findings about COVID-19 vaccine wariness mirrored previous research, especially around the themes of safety, data and government influence.
- 46% strongly agree that there isn’t enough data on the safety of COVID-19 vaccines
- 42% strongly agree that they do not know enough about COVID-19 vaccines
- 35% strongly agree that the government is too involved in vaccine decisions
Improving vaccine acceptance with targeted interventions
The 20 experiments we fielded were all grounded in significant literature from academia. In many cases, we replicated published study designs, rewritten for the vaccine decision. These behavior-change techniques are typical of what behavioral scientists and others have recommended to improve vaccine acceptance. Yet in our tests, many did not work.
Our experiments first assessed a baseline willingness for individuals to get vaccinated in the near future. Next, we exposed people, in a random order, to different scenarios designed around established behavior change techniques and then reassessed their willingness to get vaccinated. We analyzed all of this data to determine which bias prompts caused a statistically significant change in the willingness to get vaccinated. All of the tests we cover here showed a significant change at the 90%–95% confidence level.
The 7 nudges that encouraged COVID-19 vaccination
Although these validated bias triggers should be layered into pro-vaccination efforts to achieve the biggest effect, we have isolated each test to help explain how the bias nudge works. Our research reports on where these individuals transitioned from vaccine-hesitant or anti-vaccine, to willing to get vaccinated in the near future (within one month of the vaccine becoming available to them) after experiencing these nudges.
The 7 interventions that encouraged hesitant individuals to get the COVID-19 vaccine
The bias triggers that work to encourage general adult vaccines
We previously noted that extrapolating from academic research can lead you down the wrong path—this is why it’s important to test bias interventions for specific situations. For example, even though we tested the same 20 biases across COVID-19 and adult vaccines, we found only a partial overlap in successful approaches.
We found that four bias triggers had a strong impact on willingness to get an adult vaccine (shingles, HPV or pneumococcal). And only two of them were the same as what we found worked for COVID-19 vaccination: Social Facilitation and Confirmation Bias. Globally, the Social Facilitation nudge drove 18% of hesitant people to become likely to get a general adult vaccine, and the Confirmation Bias nudge drove 11% of hesitant people to become likely to get a general adult vaccine (n=2,197). Reminding people that others are watching and that their vaccination status can affect their social behaviors can motivate them to get vaccinated. Similarly, getting people to think about why someone would want to get vaccinated improves their own willingness to get vaccinated. This tactic had an even more dramatic effect for men under 50 and for respondents who described themselves as Black or Hispanic.
The 4 interventions that encouraged hesitant people to get adult vaccinations
These common tactics failed to encourage COVID-19 vaccination
While we found several significant opportunities to improve willingness to get vaccinated, we also found that a few of the more common approaches did not work in our tests.
Failed – Authority Bias: This bias assumes that people are more likely to trust information coming from an authority figure. There is no need to continue to invest in campaigns that show famous individuals such as sports stars, politicians or celebrities getting COVID-19 vaccines, as we found those messages do not increase the likelihood that people will act.
Failed – Identifiable Victim Effect: When people hear a story about a specific individual’s experience, they are more compelled to act than they would be if they heard statistics about anonymous people. Yet this approach did not inspire participants to get vaccinated. It’s just as effective to use population-level statistics to explain who is hospitalized or suffering from COVID-19 than it is to refer to individual case studies about named patients who suffered severe complications from the disease. An Identifiable Victim Effect was present among those aged 50-plus and caused previously hesitant people to become likely to get a general adult vaccine in the U.S.
Failed – Cognitive Fluency: This bias explains how those who hear messages that are simple, rhyming or repeated consider them to be more true, popular or safe. Taking their cue from common advertising techniques, these tactics did not make people more likely to get vaccinated. It would be more effective to promote clear messaging about safety and efficacy from a single, credible source.
The value of our research on vaccine hesitancy
Figuring out which nudges are effective is only half the battle. We need leaders to effectively use them. We are currently working to engage with healthcare and public health officials to incorporate these insights into policies and consumer outreach programs. I’m sharing the results of our research to encourage other stakeholders to embrace them, whether they are government leaders, healthcare professionals, religious authorities, teachers, neighbors or sons and daughters trying to persuade their parents that a COVID-19 vaccine is the safest and smartest way to protect themselves from this deadly disease.
It’s critical we embrace such insights now so we can stop doing what’s not helping and quickly pivot to powerful data-backed strategies that work. I encourage you to download the full results of our vaccine research, including the data gathered for each experiment, to fully understand the effects of these bias interventions on various populations.
Our vaccine research shows the potential for behavioral science to make an impact when the stakes are high during a pandemic. But I also hope leaders will increasingly recognize its value to change people’s actions in many areas of healthcare, whether it’s pushing people to get a flu shot or colonoscopy, take their medications or go to the doctor. This is an important time to embrace a proven and robust discipline that will tell us more about ourselves than we ever knew.
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