Exposure to dynamic social norm messages increases plant-based food choice: An online and field-based experiment

Quick-service restaurants (QSRs) are increasing the availability of plant-based options. However, there is a gap between the availability of these items and consumer demand. One strategy to promote plant-based food consumption is social norm messages which provide information about others' behaviour. This remains to be fully examined in a QSR setting, hence, across two experimental studies, we examined the effectiveness of social norm messages on increasing plant-based food choices. The effectiveness of social norm messages may vary by individual characteristics; thus, collectivism was examined as a potential moderator. Study 1 comprised an online experimental study with participants from eight countries (N = 892). Participants were asked to select a plant- or meat-based meal following exposure to either a descriptive, dynamic, or injunctive social norm message, or a no-norm control message. Questionnaire data was used to examine collectivism as a moderator. The dynamic and injunctive norm messages, but not the descriptive norm message, increased plant-based food choices in Study 1. Collectivism did not significantly moderate the relationship between plant-based food choices and social norm messages. A field study (Study 2) was also conducted. Participants were exposed to a social norm message (descriptive or dynamic) or standard-control message at order terminals in real-world QSRs. Only dynamic norms were found to increase plant-based food choices. Overall, these findings suggest that implementing dynamic social norms into real-world QSRs could be an effective strategy for increasing plant-based food consumption to improve human and planetary health. Further research examining the long-term effects on food choice is needed.