Descriptive norms for physical activity and healthy eating

While it has been long known that the behaviour of others can influence individual behaviour, norms (the views and behaviours of others) are not generally reported as strong motivators of physical activity. Using the theory of normative social behaviour as a guiding framework, the purpose of this research was to examine if descriptive norms (the perceived prevalence of others’ behaviour) would be more important in predicting activity than previously suspected. A secondary purpose was to extend this examination to another health behaviour, healthy eating. Three independent studies were conducted. The first two studies examined what individuals thought motivated their physical activity (Study 1) and eating (Study 2) as well as the relationship between descriptive norms and participants’ own activity behaviour and healthy eating intentions. Results revealed that, despite being rated by participants as less motivating, descriptive norms were stronger predictors of activity behaviour and healthy eating intentions than other well-established non-normative reasons. It also was found that descriptive norm perceptions about a group proposed to be high in group identity (i.e., friends) was most related to physical activity behaviour and healthy eating intentions. To extend these results, a third study manipulated normative and non-normative messages to examine effects on physical activity. Participants were grouped into one of four conditions (descriptive norm, health, appearance, and control) and received motivation-based email messages specific to their condition encouraging them to be active. It was hypothesized that participants in the descriptive norm condition would experience the greatest increase in physical activity but results did not support this hypothesis, as participants’ across all conditions significantly increased total physical activity after receiving the messages. A secondary hypothesis examining the focal nature of the targeted behaviours was supported in that responses to normative messages were greatest with the most focal behaviour (using the stairs). Taken together, the results of the first two studies provide preliminary evidence to suggest that the relationships between both descriptive norms and physical activity and descriptive norms and healthy eating may be going undetected. In light of the results of the third study, however, future studies are needed