Understanding the Dynamics in the Relationship between Descriptive Norms and Pro-Environmental Behaviour

The urgency to counteract climate change and other environmental problems requires large-scale changes in pro-environmental behaviour. Large-scale changes often start on a small-scale, with initially only a minority engaging in a particular action that may spread to other people. Ultimately, this can lead to widespread diffusion in society. Key determinants for changes in pro-environmental behaviour may be descriptive norms in society, the perceived engagement of others in pro-environmental behaviour. With only a minority exhibiting a “new” pro-environmental behaviour, the large-scale descriptive norm for this behaviour is likely to be weak. We expect a weak descriptive norm to inhibit behavioural changes in many other individuals, which may limit people to adopt the new pro-environmental behaviour.

We explore what factors determine whether people take a new pro-environmental behaviour despite the existing descriptive norm, and how overtime this may turn into a dynamic social norm (i.e., where individuals become aware that more and more people adopt pro-environmental behaviour), and eventually a new pro-environmental descriptive norm. We hypothesise that individuals can become motivated to adopt pro-environmental behaviour when they interact with someone who behaves accordingly, especially if that person is a relevant reference. We explore tipping points, where small changes trigger self-reinforcing mechanisms between pro-environmental behaviour and descriptive norms, leading to large-scale behavioural changes. We tested these propositions via agent-based modelling showing that the mutual influence of descriptive norms and pro-environmental behaviour forms a dynamic relationship that can explain how pro-environmental behaviour of a minority can lead to large-scale behavioural changes. Limitations and implications will be discussed.