Elsevier

Preventive Medicine

Volume 49, Issues 2–3, August–September 2009, Pages 190-193
Preventive Medicine

Do social norms affect intended food choice?

https://doi.org/10.1016/j.ypmed.2009.07.006Get rights and content

Abstract

Objective

To evaluate the effect of social norms on intended fruit and vegetable intake.

Methods

A two-stage design to i) compare the perceived importance of normative influences vs cost and health on dietary choices, and ii) test the prediction that providing information on social norms will increase intended fruit and vegetable consumption in an experimental study. Home-based interviews (N  = 1083; 46% men, 54% women) were carried out as part of the Office for National Statistics Omnibus Survey in November 2008.

Results

The public's perception of the importance of social norms was lower (M = 2.1) than the perceived importance of cost (M = 2.7) or health (M = 3.4) (all p's < 0.001) on a scale from 1 (not at all important) to 4 (very important). In contrast, results from the experimental study showed that intentions to eat fruit and vegetables were positively influenced by normative information (p  = 0.011) in men but not by health or cost information; none of the interventions affected women's intentions.

Conclusions

People have little awareness of the influence of social norms but normative information can have a demonstrable impact on dietary intentions. Health promotion might profit from emphasising how many people are attempting to adopt healthy lifestyles rather than how many have poor diets.

Introduction

Impressive health gains stand to be made if even small changes in behaviour are achieved on a population-wide basis; yet providing information about the adverse health effects of poor diet or lack of exercise has limited impact on behaviour (Little et al., 2004). Novel strategies for behaviour change are urgently required. One under-used approach in the area of diet or exercise is normative social influence.

A number of studies have demonstrated correlations between internalised social norms (‘what other people think I should eat’) and dietary choices in terms of the amount people eat (Conner et al., 1996, Herman and Polivy, 2005, Povey et al., 2000), but few studies have examined associations between descriptive social norms (‘what I think other people eat’) and diet (Rivis & Sheeran, 2003), and none has addressed fruit and vegetable intake. There have also been no experimental studies to establish that associations are causal. However, there is evidence for the influence of social norms on binge drinking (Neighbors, Larimer, & Lewis, 2004), sun protection (Mahler, Kulik, Butler, Gerrard, & Gibbons, 2008), energy conservation behaviours (Goldstein et al., 2008, Nolan et al., 2008, Schultz et al., 2007), and the amount of food consumed at a meal (Herman et al., 2003, Vartanian et al., 2008). These effects have been found not only with direct observation of others but also with written information (Nolan et al., 2008). One interesting feature of normative influence is that its effect appears to be outside of conscious awareness (Aarts & Dijksterhuis, 2003). In fact people often deny being influenced by others' behaviour; and at least in the energy conservation context, are more likely to attribute their decisions to motives such as ‘concern for the planet’ (Nolan et al., 2008).

The present study investigated the impact of social norms on intended food choice. We first assessed people's perceptions of normative influences on their fruit and vegetable intake, and then used an experimental design to test the effect of normative information on intentions to eat fruit and vegetables in the future. Based on similar work on energy conservation (Schultz et al., 2007, Nolan et al., 2008), we predicted that people would perceive social norms (‘how much fruit and vegetables others eat’) as less important than health or cost, but that normative information would actually show a positive effect on dietary intentions.

Section snippets

Study sites and sample

The study was embedded in the Office for National Statistics (ONS) Omnibus Survey which draws a monthly sample from the Royal Mail's Postcode Address File (PAF) of over 27 million households in Britain. Each month, 67 postal sectors and 30 addresses within each sector are chosen randomly to give a final sample of 2010 addresses. Advance letters are sent to all addresses, prior to interview, giving a brief account of the survey. One person aged 16 or over per household is selected at random by

Stage 1

As predicted, there was a significant difference between the ratings of the four perceived determinants (within-subject F[2,2122] = 617.4, p < 0.001). Paired t-tests showed that the perceived importance of social norms (mean = 2.1) was significantly lower than the perceived importance of cost (mean = 2.7; t = 16.4, p < 0.001) or health (mean = 3.4; t = 35.8, p < 0.001), in deciding how much fruit and vegetables to eat. Effect sizes for the differences between the perceived effect of norms and perceived effect of

Discussion

This general population sample rated the influence of social norms as less important than health or value for money in deciding how much fruit and vegetables to eat. The finding that awareness of social influence was low is consistent with studies of energy conservation (Schultz et al., 2007, Nolan et al., 2008) and a study specifically looking at the amount of food consumed at a meal (Vartanian et al, 2008). However, whether the lack of endorsement of social normative influences represents a

Conclusions

The finding that intended fruit and vegetable intake was increased following social normative information – albeit only in men in this study – suggests that campaigns emphasising how poor our diet or exercise habits are (e.g. ‘a nation of couch potatoes’; 9 out of 10 children will become overweight adults) could be less useful in motivating change than media campaigns emphasising how many people are making positive efforts.

Conflict of interest statement

None declared.

Acknowledgments

The Omnibus Survey team at the Office for National Statistics. The study was funded by Cancer Research UK.

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