Niemiec, R. M., Champine, V., Vaske, J. J., Mertens, A. (2020). Does the impact of norms vary by type of norm and type of conservation behaviour? A meta-analysis. Society & Natural Resources, 33(8), 1024-1040.
In a nutshell: This meta-analysis explores three types of norms – subjective or injunctive norms, descriptive norms, and personal norms – and their effect on conservation behaviour intentions. In general, personal and descriptive norms had a greater influence on intentions than subjective norms, and the effect of subjective norms was reduced when personal and descriptive norms were included in behaviour intention models.
Throughout the conservation psychology literature and beyond, norms are seen as a key driver of conservation behaviour. There are three commonly discussed kinds of norms: subjective or injunctive norms, descriptive norms, and personal norms.
Subjective or injunctive norms refer to perceptions of whether other important people (e.g. respected figures, friends, family) think a certain behaviour should be performed. These norms are a key component in the commonly used theory of planned behaviour and theory of reasoned action. Descriptive norms refer to the perceptions of how common a behaviour actually is in the community. Personal norms refer to individual standards for behaviour, which often flow from an individual’s personal values and awareness of the consequences of certain actions (e.g. sense of responsibility, anticipated guilt or pride).
In their meta-analysis, Niemiec et al. 2020 focus on 100 studies that test the influence of subjective and injunctive norms on conservation behaviour intention, including some studies that also incorporate descriptive and personal norms. They explore how the relationship between the three norm types and conservation behaviour intention varies across different conservation behaviours, including:
- Fishing, forestry, and agriculture (e.g. soil conservation efforts);
- Recreation (e.g. leave no trace behaviours);
- Household conservation (e.g. recycling, waste reduction);
- Green consumerism (e.g. organic foods, eco-friendly hotels);
- Everyday public conservation (e.g. transport choices); and
- Social/civic environmental action (e.g. citizen science, advocacy)
Niemiec et al. 2020 found that:
- 62% of subjective norm evaluations found a significant relationship between subjective norms and behavioural intention
- The effect of subjective norms was relatively consistent across behaviour types (59-69%)
- 88% of descriptive norm evaluations found a significant relationship between subjective norms and behavioural intention (n = 5)
- 87% of personal norm evaluations found a significant relationship between personal norms and behavioural intention
- The effectiveness of subjective and personal norms varied slightly across behaviour types (e.g. personal norms worked better than subjective norms for green consumerism and household conservation, n = 6)
- When personal or descriptive norms were in models alongside subjective norms, personal and descriptive norms had significantly greater effects than subjective norms
The findings suggest that researchers should consider descriptive and personal norms as potential drivers of behavioural intention, given their effectiveness across many of the evaluated studies. The study also shows that further experimental testing is needed to explore the relationships between the three norm types, and test how these may vary across different behaviour types.
However, the study supports the idea that normative interventions may be most effective if they aim to activate all three kinds of norms together.