EMOTIONS ARE POWERFUL DRIVERS of judgment and choice. Advertisers rely on them, and public leaders do the same when communicating risks. Public service announcements, in particular, often use emotional appeals to influence behavior. Yet until recently, a scientifically tested framework for identifying which emotions help—or hinder—desired outcomes was missing. At Harvard Kennedy School, research led by Jennifer Lerner—the Thornton F. Bradshaw Professor of Public Policy, Management, and Decision Science—is filling this gap, with implications for both public health and national security.
HKS doctoral students have been central to these advances. Smoking remains one of the world’s leading preventable causes of death, claiming more than 8 million lives each year and imposing more than $1 trillion in annual economic costs worldwide. Research from Lerner’s lab, published in the Proceedings of the National Academy of Sciences (PNAS), shows that emotions influence smoking in striking ways: messages evoking gratitude can reduce cigarette use, while those evoking sadness can heighten cravings. Ke Wang PhD 2024 led the research on gratitude, work that formed the basis of his dissertation and earned the 2025 Society for Affective Science Best Dissertation Award. Charles Dorison PhD 2020 led the research on sadness, and current candidate Sarah Chen (PhD expected 2026) is extending this line of inquiry into the role of negative emotions. Together, these projects demonstrate how decision science can strengthen public health communication by providing an evidence-based foundation for message design.
The work also extends into national security, where the focus has been less on emotion and more on helping leaders design decision environments that improve decision quality and strengthen organizational effectiveness in an uncertain world. Taking a public service leave from Harvard, Lerner served as the first-ever chief decision scientist for the U.S. Navy and has held advisory roles with the U.S. Naval War College and for the secretary of the Navy. She also chaired the dissertations of several active-duty military officers who earned their PhDs from HKS and are now applying decision science in strategic and operational contexts. In addition, at the invitation of the U.S. Air Force, Lerner has for the past five years taught key concepts from decision science in an Air Force course for rising two-star generals and their civilian counterparts. Through HKS Executive Education, she also helps leaders from government, business, and nonprofit organizations apply decision science tools to their own high-stakes challenges. By conducting rigorous research aimed at addressing pressing challenges, Lerner and her HKS doctoral students illustrate how the School advances its mission: equipping public leaders to improve outcomes when the stakes are highest.
Banner Image: Jennifer Lerner with Chief of Naval Operations Admiral John Richardson, the service’s top military officer, during one of her visits to the Pentagon. Photo by Raymond Diaz III
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Celebrating service through a historic new fellowship
PEOPLE DEDICATED TO PUBLIC SERVICE of all kinds make up the backbone of the country. There are more than 18 million living veterans in the United States. Around 20 million people work in state or local government. Roughly 3 million people work in federal government.
Harvard Kennedy School recognizes and celebrates this dedication to service. The American Service Fellowship is a new initiative that will provide full scholarships for at least 50 public servants and military veterans to enroll next fall for a one-year, fully funded Mid-Career Master in Public Administration degree.
This fellowship is the largest single-year scholarship program in HKS history, and it is open to those who have served at least seven years in the U.S. armed forces, including veterans or active-duty military; in federal, state, or local government, including teachers and law enforcement; or in the Peace Corps, AmeriCorps, and other full-time civilian service programs.
If you know anyone who would be a good fit for this program, please help us spread the word. Find more information at ken.sc/service.
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