The World Health Organization says smoking is the leading cause of global preventable death, killing up to 8 million people prematurely every year—far more than die in wars and conflicts. Yet the emotions evoked by national and international anti-smoking campaigns and the impact of those emotions has never been fully studied until now. HKS Professor Jennifer Lerner, a decision scientist who studies emotion, and Vaughan Rees, the director for the Center for Global Tobacco Control at the Harvard Chan School of Public Health, say their research involving actual smokers in the lab shows that sadness—the emotion most often evoked in anti-smoking ads—can actually induce people to smoke more. Lerner and Rees’ research also found that evoking gratitude, an emotion that appears to function in nearly the exact opposite manner to sadness, made people want to smoke less and made them more likely to join a smoking-cessation program. Lerner and Rees join host Ralph Ranalli on the latest episode of the HKS PolicyCast to discuss their research and to offer research-backed policy recommendations—including closer collaboration between researchers who study emotion science, which is also known as affective science, and agencies like the Centers for Disease Control. Jennifer Lerner’s Policy Recommendations: ● Promote active collaboration between researchers and public health agencies (e.g., CDC, FDA) to develop health communications that leverage the most current, research-backed findings from affective and decision science. ● Rigorously assess not only the benefits of public service announcements but also potential harms. Assessments often overlook the emotional distress these messages can cause, despite the potential of distress to undermine desired outcomes. Vaughan Rees’ Policy Recommendations: ● Expand research into integrating emotion-based strategies, such as gratitude exercises, into school-based prevention programs for adolescents to reduce the risk of tobacco and other substance use, as well as risky sexual behaviors. ● Introduce research-backed, emotion-based components in cessation counseling and support systems, helping individuals better manage high-risk situations and maintain abstinence after quitting.