Cutting calories: Exploring social comparison and self-comparison nudging in online grocery shopping contexts

Abstract

Public health scholars have indicated that new nudging research is needed to help avert a global obesity crisis. We test a novel form of social influence nudging—out-group social comparisons—as well as goal-based self-comparisons to understand how to best nudge calorie reduction across broad populations. 650 adults in the United Kingdom (UK) and United States (US) were recruited to participate in a split study on social comparison and self-comparison nudging in online grocery shopping contexts. Our overall results showed that those randomly assigned to either the in-group or out-group social comparison condition were significantly more likely to reduce calories than those randomly assigned to the control condition which displayed only calorie information (p = .0041), indicating that calorie information paired with social comparisons drives healthier choice outcomes. We show that self-initiated Challenge Teams serve as an optimal way to facilitate social comparisons ethically, with an 86% acceptance rate in the US and 76% acceptance rate in the UK. Finally, we indicate that goal-based self-comparisons may be an effective nudging alternative for individuals who do not wish to join social Challenge Teams and may have a low-to-moderate desire to affiliate with others.