Comparison with neighbors can increase climate-friendly behavior

International meta-analysis synthesises data from 79 studies

Social comparisons are increasingly employed as an intervention strategy and have proven effective in changing one’s behaviour, also with regard to adopting a more environmentally conscious lifestyle. This is one of the key findings of an international meta-study conducted by a team in the Clinical Psychology, Psychotherapy, and Health Psychology research group at the University of Münster, which evaluated data from 79 studies from various behavioural sciences. The results have been published in the journal Nature Human Behaviour. The study was motivated by the question of how far social comparison can facilitate changes in behaviour. Comparing ourselves to others is a natural tendency, especially when it comes to motivating ourselves or coping with a crisis. Social comparisons can also be strategically employed to encourage changing one’s habits.

"Comparing our own behaviour with that of others, for example in terms of health, alcohol consumption or exercise, can lead to positive habit change. While most of the evidence published to date supports its short-term efficacy, there is only little published data on long-term effects," explains Dr Thole Hoppen, lead author of the study. In terms of climate-friendly behaviour, however, there is already a growing body of evidence for such long-lasting changes. One example is information about the electricity consumption of neighbouring households together with the annual electricity bill, according to co-lead author Rieke Cuno: "If I read that my neighbours have significantly lower average electricity consumption than I do, this can motivate me to use less energy." Short-term effects on health behaviour were seen, for example, in the use of sports apps on smartphones that allow users to compare their performance with others. Social comparisons can also lead to better exam results. "Students tend to achieve better results if they have compared their performance in advance with fellow students who have a similar level of performance," adds Thole Hoppen.

"The more often people receive information on social comparison, the more likely they are to adjust their behaviour," says Nexhmedin Morina, senior author of the study. However, the standard must be achievable and realistic for the intervention technique to be most impactful. Focusing on desired behaviour is also more effective than focusing on undesirable behaviour. "For example, people tend to be more motivated to cycle more than to give up their cars," says Rieke Cuno. If we want to encourage positive behaviours, it is better to focus on what we want to do more of, rather than what we want to avoid.

Method

For its meta-study, the team searched the databases MEDLINE, PsycINFO and Web of Science and evaluated data from 79 randomised controlled studies. These studies examined the effects of social comparison on climate protection, health, service and performance behaviour. Long-term data are currently only available for the first two domains of behaviour. In total, the research team considered data from more than 1.3 million study participants between the ages of 9 and 65, with an average age of 39. Most of the accumulated data come from the US and other high-income countries. No behavioural differences were found in relation to gender, age or nationality.

Original publication

Hoppen, Thole H..H.H, Cuno, Rieke M., Nelson, Janna, Lemmel, Frederike, Schlechter, Pascal, Morina, Nexhmedin Morina (2025): Meta-analysis of randomized controlled trials examining social comparison as a behaviour change technique across the behavioural sciences. Nature Human Behaviour; DOI: 10.1038/s41562-025-02209-2.