Nudges can be useful for a lot of things. Offered at the right moment, they can encourage us to start a new diet, break an old habit, or venture out of our comfort zone and discover a bold new world. But are the little prods that are so useful in our daily lives strong enough to affect public health choices in a global pandemic? For Anton Ivanov it was a question worth considering. And like many good ideas these days, it started with a simple glance at his phone.

“I was walking on the beach and checking my Instagram account,” said the Gies assistant professor, who was on a family vacation in Florida when he first noticed the university posting pictures of campus life with facemasks. It was the summer of 2020, just before the first semester that would test the school’s ability to function in a global pandemic. And in the warm summer weather with no masks in sight, the images stood out.

As someone who teaches social media strategy, he knew it wasn’t a random decision. He suspected that the university was attempting to set the expectations for campus life during a global pandemic, and perhaps nudge students to practice habits that could lower disease transmission. So, he decided to follow his hunch and see if the same visual cues that drive fashion and other decisions could impact public health.

It was an important question to ask, because more direct efforts to foster mask wearing were meeting stiff resistance, as a simple tool for disease prevention became the latest flashpoint in a country deeply divided by politics. While some saw mask mandates as a prudent health measure, others saw them as an infringement of their personal liberty. And the ensuing struggle quickly became a dilemma for store clerks, flight attendants, and others who were suddenly charged with policing unpopular policies as part of their regular job.

“That’s the beauty of nudges as a concept,” said Ivanov (right). “Nudges represent a form of intervention that does not make people do something. Instead, it shows them how other members of the community are behaving on a certain aspect, and through that, they can exercise their choice.”

Giving people that choice, Ivanov says, is oftentimes more effective than simply imposing mandates. It’s basically the difference between encouraging kids to eat healthy snacks and ramming them down their throat. If you want gets to eat broccoli, you have to make them want to eat broccoli.

Nudges can provide a way for stores and other public institutions to thread a tricky needle, using social media to promote a change in behavior rather than demanding it. But that only works if nudging works. And Ivanov and his team were able to show that it did.

By comparing nearly 32,000 Instagram images from 117 universities with COVID positivity rates at those institutions, they discovered there was an inverse correlation. The more that universities used visual nudges to encourage mask wearing, the lower the campus positivity rate. And the effect was notable, with positivity rate decreases by as much as 25% on average.

Of course, some conditions need to be met to make visual nudges effective, says Ivanov. First, you need to get those images to where your audience will see them. In this case, the effect was most pronounced with Instagram, because of its heavy use of images and because students tend to follow their university’s Instagram account more than its other social media platforms.

Next, the messaging needs to be both frequent and consistent. “Our empirical results show that four to five weeks of accumulation usually creates the momentum required for people to bring that topic to the top of their agenda.”

Then there’s one last important factor, and that’s the element of time. Habits seldom change overnight, which means there’s a delay between visual nudging and any change in public behavior. “In our research we were able to show that, on average, the visual nudges should be communicated three to five weeks before the anticipated exposure.” That’s something that Ivanov says that Illinois did particularly well.

“UIUC started sharing more content way in advance compared to other schools, which started doing that when the semester basically began. That was too late for them to do so and achieve the same affect.”

Ivanov’s study, “The Informational Value of Visual Nudges During Crisis: Improving Public Health Outcomes Through Social Media Engagement Amid COVID-19,” was recently published in Production and Operations Management. Hopefully, it will provide a roadmap for future companies attempting to navigate difficult issues in divided times.