Informal messaging, the thinking goes among academics and practitioners, is more effective than dryly formal letters. But when it comes to government communications, it may be time to put away colorful graphics and more casual language to spur recipients to respond, according to new research co-authored by scholars from the Kennedy School’s People Lab.

In a series of studies, a group including The People Lab’s Elizabeth Linos, the Emma Bloomberg Associate Professor of Public Policy and Management, and Jessica Lasky-Fink, have found that people see formal government communications as more credible and important than informal communications—and are therefore more likely to act. The researchers call this phenomenon the “Formality Effect.”

To test for it, the researchers first asked whether people had a shared understanding of formality when it came to both language and design. (The study’s authors also include the University of London’s Chris Larkin, the U.S. Department of Veterans Affairs’ Lindsay Moore, and Elspeth Kirkman of Nesta, an innovation foundation based in the United Kingdom.) They presented online study participants with letters that had either formal or informal language and design elements. Subjects who received letters with more formal aesthetic choices—think standard black Times New Roman font and no graphics or special formatting—recognized them as more formal than letters using elements like eye-catching color, graphics, formatting, and fun fonts. Letters that used more complex and impersonal language were also seen as more formal than less complex and more personalized messaging.

Elizabeth Linos.

“Recipients view the source of a formal letter as more competent and trustworthy, and view the request itself as more important to take action on, despite no change in comprehension nor in perceived ease of taking action.”

Elizabeth Linos

After determining that a shared understanding of formality exists, the researchers ran a series of field experiments partnering with local governments to understand the impact of formal communications. In one experiment, the partner city sent 10,000 businesses either a formal or informal letter to encourage them to register as a local, minority-owned, or woman-owned business. The researchers write, “The more formal letter was black-and-white, addressed ‘Dear Business Owner,’ and included about 260 words. The more informal letter cut the length by half, included a personalized greeting, and used informal tone and punctuation (i.e., ‘We want to work with you!’ and ‘Good luck in the new year!’). It also included colorful design elements including a red box around the call to action, and red font emphasizing the purpose of the letter.” Counterintuitively, the businesses who received the formal letter were 25% more likely to register than ones that received the informal one.

Another study sent either formal or informal letters to 35,172 residents in a partner city encouraging them to sign up for a medical transport program. As with the business owner study, the recipients of the formal letter were 45% more likely to sign up. The researchers also conducted an experiment to see whether recipients of a formal or informal letter would be more likely to visit a website to learn about the California Earned Income Tax Credit, using a sample of 20,000 households. People who received the formal letter were 28% more likely to visit the site.

A graphic showing two documents, one with formal design and another with a more colorful and chaotic design.

Importantly, these results all defied the expectations of scholars and practitioners. In a study of 351 academics, researchers, and practitioners, over 80% predicted that the informal letter from each field experiment would be more effective.  

In addition, the researchers conducted two further online experiments to understand mechanisms: one examining people’s expectations of government communications—which found that people expect these messages to be more formal by nature—and another that tested whether people associated formality with credibility and importance, which found this to be the case.

The series of studies provided evidence that “recipients view the source of a formal letter as more competent and trustworthy, and view the request itself as more important to take action on, despite no change in comprehension nor in perceived ease of taking action.”

“These findings have immediate implications for government communicators and open the door for a renewed focus on how the design and presentation of information impacts behavior,” the authors write.

Banner photograph by Geraldine Wilkins/Los Angeles Times/Getty Images

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