Social proof in the supermarket: Promoting healthy choices under low self-control conditions

• Under low self-control conditions, social proof may benefit healthy food choices.
• We show that this finding holds in a supermarket setting with a community sample.
• Social proof seems a promising method to provoke healthy choices in the field.

Under low self-control conditions, people often favor tempting but unhealthy food products. Instead of fighting against low self-control to reduce unhealthy food choices, we aim to demonstrate in a field study that heuristic decision tendencies can be exploited under these conditions. To do so a healthy product was associated with a social proof heuristic, referring to the tendency to adopt the option preferred by others. A healthy low-fat cheese was promoted with banners stating it was the most sold cheese in that supermarket. A state of low self-control was experimentally induced in the supermarket, and compared to a high self-control condition. Participants low in self-control were more likely to buy the low-fat cheese, when this product was associated with the social proof heuristic, compared to when it was not. This suggests that under low self-control conditions, presenting social proof cues may benefit healthy purchases.