The influence of social norms varies with “others” groups: Evidence from COVID-19 vaccination intentions
The theory that health behaviors spread through social groups implies that efforts to control the pandemic through vaccination will succeed if people believe that others in their groups are getting vaccinated. But “others” can refer to many (often overlapping) groups, such as one’s family, neighborhood, city, state, or political party. These distinctions and their relationship to behavior are understudied in the social norms and public health literature. One challenge to studying them is that many factors may confound making inferences from observed relationships between perceived social norms (what people believe others do) and intended behaviors (what people themselves will do) because there are often plausible common causes for both. For example, vaccination intentions and perceptions of one’s social group’s intentions could both increase with age, since age is a known COVID-19 risk factor and people may know more people in their own age groups. We address these issues by applying a matched design that approximates pair-randomized experiments to survey data collected in the US during late fall 2020 (N = 890) and spring 2021 (N = 996). We find that a strong relationship between perceived vaccination social norms and vaccination intentions remains when controlling for a host of real risk factors as well as dimensions known to predict COVID-19 preventive behaviors even though they are not associated with risk. The strength of the relationship declines as the queried social group grows larger and more heterogeneous. The relationship for co-partisans is second in magnitude to that of family and friends among Republicans but undetectable for Democrats. Sensitivity analysis shows that these relationships could be explained away only by an unmeasured variable with large effects on both social norms perceptions and vaccination intentions (odds ratios between two and nineteen times), and a prediction from the false consensus interpretation that intentions cause perceived social norms is not supported. We discuss the implications for public health policy and understanding social norms.