Abstract
Smartphone apps that support health behavior change efforts often provide opportunities for users to compare their behaviors and progress to that of other users (i.e., social comparison). At present, however, available literature on features of these apps has two main limitations: (I) it shows little consistency in its application of the term social comparison, and (II) it does not take into account key aspects and consequences of social comparison that could improve user engagement and behavioral outcomes. In this piece, we provide examples to illustrate the problems in each domain of limitation, and we identify critical aspects of the broader social comparison literature that could inform the tailoring of social comparison features to individual users and contexts.