If you want to get people’s attention to address a problem, making it seem as big as possible is a nearly universal reflex.

But it’s almost certain to backfire, according to Northwestern’s Lauren Eskreis-Winkler, Cornell predoctoral scholar Luiza Tanoue Troncoso Peres, and Chicago Booth’s Ayelet Fishbach. In a study, they name this the “big problem paradox.”

Across more than a dozen experiments, they find that describing how big a problem is tends to lessen people’s estimates of its severity.

“When you learn there are many people who don’t finish college, you say, ‘Probably it won’t affect their lives that much,’” Fishbach says. “When we remind you that air pollution is common, you say, ‘Well, I guess it’s not so bad.’” Big numbers often give you a false sense of security, and the way a problem is communicated is often at odds with the intended message, according to the study.

In their experiments, the researchers told participants the size of a range of problems, including city-wide building code violations; children who aren’t vaccinated against measles, mumps, and rubella; patients who don’t take their medications; drunk driving; adultery; and positive screenings for a breast cancer gene mutation. No matter the problem, people who learned it was prevalent inferred that it caused less harm.

Don’t mention it 

In several experiments, participants viewed problems as less harmful after being told how common they were.

In one experiment, the researchers asked participants to consider a woman who learned that she had a genetic mutation increasing her risk of breast cancer. They were told to estimate how likely it was that she would develop breast cancer. They then learned that “over 300,000 women in the United States have a mutation in this gene.” The researchers asked the participants to make a second guess about the woman’s breast cancer risk. On average, participants underestimated the risk the first time and lowballed it even more after reading about the prevalence of the gene mutation.

In another experiment, participants estimated how likely a man who drives drunk is to cause a fatal accident. The researchers then informed participants that 4.2 million people drive while intoxicated every month, which prompted the revised estimates to drop.

Previous research projects, including one led by University of Pennsylvania’s Jeremy D. W. Clifton, have made the case that people generally believe that the world is safe. The latest findings present a new wrinkle: If something is common in a safe world, people think that it must also be safe.

Indeed, when safety is no longer assumed, the effect attenuates, the researchers find. When they described a rich, suburban family that found polyamide and several other chemicals in their tap water, they observe that participants who considered the prevalence of contamination were less likely to think the family would get sick and were more likely to think that the government had addressed the problem. But when participants imagined this to be happening in a poor community, for which a safe environment is not assumed, participants no longer thought that water contaminants, if prevalent, would cause less harm. Big problems only seem less problematic as long as people assume a generally safe environment, the researchers contend.

To create effective public service announcements or charity advertisements, organizations may need to rethink which statistics to highlight, the findings suggest. And the study holds a lesson for everyone: Just because a problem is common doesn’t mean it’s something to safely ignore.

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