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Social comparisons better than knowledge in climate change mitigation interventions


In interventions designed to encourage more sustainable and climate-smart behaviour, examples of what other people are doing and financial ‘carrots’ are more important than providing knowledge and facts. This has been shown in an international second-order meta-analysis of more than four hundred primary studies. However, all types of climate mitigation interventions have a relatively small effect on how people behave.

Changing behaviours is essential if we are to meet our climate targets. Information and other types of interventions designed to influence behaviour are some of the tools being used. In a meta-analysis study, researchers from Cambridge and Yale universities and the University of Gothenburg analysed what makes a good intervention if your aim is to change people’s behaviours.

The results showed that intervention techniques based on social comparisons and financial incentives are more effective than interventions that focus on knowledge about what is ‘right’ or ‘good’.

“Learning that people around us have started choosing vegetarian food or cycling to work is often a better motivation for getting people to change their behaviours,” says Magnus Bergquist from the University of Gothenburg.

Together with colleagues in the UK and the USA, he compiled ten meta-analyses that included a total of 430 primary studies on proenvironmental behavioural changes in people’s everyday lives.

The meta-analyses also showed that these interventions generally have a relatively small effect on people’s behaviours. Compared to those who had not participated in the interventions, people who had increased their proenvironmental behaviours by just 7 percentage points on average. The interventions were about recycling, choosing a more sustainable transport option, or saving electricity for example.

The effect was more pronounced in small-scale interventions, with fewer than 9,000 participants, than in larger ones.

“One explanation for this may be that small-scale studies are more often based on direct techniques such as face-to-face interactions, which have a greater chance of influencing behaviour,” says Magnus Bergquist.

Facts in brief

The study: “Field interventions for climate change mitigation behaviors:

A second-order meta-analysis” is published in Proceedings of the National Academy of Sciences of the United States of America: