JMIR Publications

ABSTRACT

Background:

Walking is a simple but beneficial form of physical activity (PA). Self-monitoring and providing information about social norms are the two most widely used “mobile health (mHealth)” strategies designed to promote walking behavior. However, previous studies could not discriminate the effect of single self-monitoring from that of the combination of the two strategies, though the latter was frequently used on various social media platforms. Moreover, any previous findings that have addressed this topic have not been applicable to the specific needs of Chinese culture. Some essential moderators, such as gender and group identity, were also overlooked.

Objective:

The aim of this study was to investigate the effectiveness of social norm and self-monitoring interventions on walking behavior. We also investigated the moderating effect of gender and group identity with the overall aim of providing guidance for optimal mHealth intervention projects in China.

Methods:

In two longitudinal tracking studies, college students wore trackers to record their daily step counts during the baseline, intervention (14 days) and after-effect stages. In each study, participants were random allocated to one of three groups: a self-monitoring group and two social norm intervention groups. Participants in two intervention groups received different social norm information of step rankings of their group members during the intervention stage, according to their grouping (Study 1) or type of social norm information (Study 2). In Study 1, participants were grouped by the PA-level within group members (PA-consistent vs. PA-inconsistent), while in Study 2, participants were grouped by whether the social norm information they received was gender-specific (gender-consistent vs. gender-inconsistent).

Results:

For males (n = 54) in Study 1, the effects of pure self-monitoring on walking were short-lived (a significant decrease from baseline to intervention, change of slope = -1422.16, P = .02). However, when this was supplemented with social norm information the beneficial effects of self-monitoring could be maintained (no significant decreasing, ps > .05) regardless of group consistency. For females (n = 63), social norm information did not provide any extra benefit beyond self-monitoring (no significant change, ps > .05). Indeed, females exposed to social norm information that was PA-inconsistent were found to walk less (slope during intervention = -122.18, P =.03). In Study 2, we observed a similar pattern in terms of how social norm information and self-monitoring impacted walking in males (n = 88). We found a decrease in the self-monitoring group, change of slope = -151.33, P = .08; but no decrease in the two social norm intervention groups. However, among females (n = 92), social norm information that was gender-consistent resulted in an unexpected backfire effect (slope during intervention = -143.68, P =.03).

Conclusions:

We found that, compared with self-monitoring, social norm information is only beneficial in promoting walking among males. In addition, we found that a high sense of group identity does not guarantee an improved effect on PA. Clinical Trial: This study was approved by the Institutional Review Board of the Institution of Psychology, Chinese Academy of Sciences, and all participants took part in the study voluntarily and completed written informed consent.