Step by step: Applying a stage-based approach to improve the effectiveness of social norm interventions in encouraging sustainable consumer behaviours.

Student thesis: Doctoral ThesisPhD


High levels of meat and dairy consumption have significant impacts on both environmental and health factors. In areas where meat and dairy intake is high such as the UK, reductions on meat consumption could significantly contribute to reducing greenhouse gas emissions, nitrogen pollution and saturated fat consumption. This thesis therefore focuses on a novel approach using social norms. We link different social norms to their role in encouraging individuals through the process of behaviour change to reducing their meat consumption. This context is used to contribute to theoretical discussions of social norms and the stages of change model as well as sustainable consumption more generally. Social norms are understood as an individual’s perception of behaviours that others approve or disapprove of (injunctive social norms) or what others are doing (descriptive social norms). Injunctive and descriptive norms can both encourage sustainable consumption behaviours but in different ways. Extant research has shown some inconsistent results in the social norms literature, for example there are contradictory results in relation to towel reuse & energy reduction. These inconsistencies suggest that our understanding of the operation of social norms may be limited, and as such further investigation is required to establish when social norms approaches are likely to be most effective and why. One area that social norm intervention studies have failed to take into account is the dynamics of change already taking place within the populations that they target. Therefore, in contrast to existing studies on social norms our approach understands behaviour change as a process as opposed to an event, where there are several distinct stages of change. This perspective is informed by evidence that meat reducing behaviours are adopted in a manner consistent with the self-regulated model of behaviour change This suggests that understanding the dynamics of change is crucial to determine what factors are most likely to change individuals behaviour, and thus how social norm interventions should be targeted for maximum effect. We suggest that different social norms will become more or less effective depending on the stage of change the individual they are targeting is at due to the fact that they play different roles at the different stages of behaviour change. We explore the role of social norms in the stages of change model over three empirical studies. Firstly, we look at how descriptive and injunctive norm interventions influence the different transition points in the stages of change model. We then undertake a longitudinal study looking at how injunctive norms differently impact meat consumption depending on the stage of change of the individual they are targeted at. Finally, we model how injunctive, descriptive and trending models operate in the stages of change process to explain the mechanisms of how social norms assert influence at the different stages of change. We find that social norms do become more or less effective depending on the stage of change they are targeted at and find significant relationships in our modelling paper that explain the role of each different type of social norm. With these results we contribute both to the understanding of how social norms influence sustainable consumer behaviours as well as adding a new understanding of the importance of social norms in the stages of change model. This could have significant implications for social marketers and policy makers alike as they look to encourage sustainable consumption behaviours.
Date of Award24 Jun 2020
Original languageEnglish
Awarding Institution
  • University of Bath
SupervisorJudith De Groot (Supervisor) & Krista Bondy (Supervisor)


  • Sustainability
  • Consumer Behaviour
  • Sustainable consumption
  • Social Norms
  • environmental psychology
  • consumer psychology

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