EXPRESS: The Uptrend Effect: Encouraging Healthy Behaviors Through Greater Inferred Normativity

Only a minority of Americans are adequately engaging in activities experts recommend to curb preventable disease, such as consumption of healthful foods and regular physical exercise. This poses a challenge for policymakers and social marketers alike, given the substantial impact descriptive norms have on behaviors in the health domain. We propose a new way to address this challenge by identifying what we call the “uptrend effect.” This effect encourages descriptively non-normative, healthy behaviors through uptrend messaging that makes salient actual increased engagement in those behaviors over time without referencing an objective descriptive norm. Across seven experimental studies, including studies conducted in the field and measuring real behaviors, we demonstrate that uptrend messaging leads recipients to infer greater descriptive normativity for the target behavior, which subsequently improves engagement. We identify theoretically and practically relevant boundary conditions, showing that the uptrend effect is attenuated when the growth in a behavior is driven by a dissimilar group or when the message explicitly states a descriptive norm. We also demonstrate that uptrend messaging outperforms other norm-based approaches. Our theory and findings inform scholars, policy makers, and marketers by providing actionable and easy to implement techniques to encourage behaviors that improve consumer quality of life.