Abstract Prompts to evaluate ourselves relative to others (i.e., social comparison) are increasingly engineered into our daily lives to promote specific behaviors, including in digital health technologies and health behavior change interventions. Despite its ubiquity, however, we do not yet understand how social comparison affects health behavior, including its demonstrated negative effects. Our poor understanding of the mechanistic pathway linking social comparison to health behavior limits the efficacy of many of our chronic disease prevention and intervention efforts. The proposed DP2 New Innovator Award will address the critical and overlooked opportunity to understand how social comparison affects health behavior, by introducing a new paradigm for research in this area. The traditional approach to studying the effects of social comparison uses methods that describe static differences between people, which cannot identify the nuances of what happens when comparison occurs in daily life. By assessing the complexities of social comparison and health behavior as they occur (using ambulatory, naturalistic assessment), and embedding a randomized experimental design, the proposed series of iterative studies will finally identify the unknown causal, mechanistic pathway(s) from social comparison to health behavior. This novel approach will be applied to the exemplar of physical activity leaderboards – a widely disseminated method for activating social comparison that has shown both positive and negative effects on physical activity – to understand how social comparison affects physical activity behavior among insufficiently active adults (total N = 300). This innovative approach will be guided by the PI’s new, detailed theoretical model of how social comparison affects health behaviors in the natural environment. Consequently, the proposed work will have a meaningful public health impact, by generating evidence- based recommendations for the optimal use of comparison to promote healthy behavior while minimizing its negative consequences. This work will also advance behavioral science and related fields by providing a roadmap for testing the effects of social comparison on other health behaviors and outcomes.

Narrative Prompts to evaluate ourselves relative to others (i.e., social comparison) are increasingly engineered into our daily lives to promote specific behaviors, including in digital health technologies and health behavior change interventions, but we do not yet understand how social comparison affects health behavior – including its demonstrated negative effects. The proposed DP2 New Innovator Award will address the critical and overlooked opportunity to understand how social comparison affects health behavior in the natural environment, by introducing a new paradigm for research in this area that is guided by a novel, detailed theoretical model. Using physical activity behavior as an exemplar, the proposed work will have a meaningful public health impact by generating evidence-based recommendations for the optimal use of comparison to promote healthy behavior while minimizing its negative consequences.