Adjusting for Publication Bias Reveals Evidence Against Social Comparison As a Behaviour Change Technique Across the Behavioural Sciences

Social comparison is increasingly used as a behaviour change technique (SC-BCT) yet its true efficacy remains unclear. To address this concern, Hoppen and colleagues1 performed a comprehensive meta-analysis of 79 randomized controlled trials involving over 1.3 million participants. Hoppen and colleagues “found evidence supporting the efficacy of SC-BCTs in shaping behaviour in the desired direction”. However, their own risk of bias assessment revealed that “most trials (k = 66; 84%) had some concern of bias regarding selection of the reported result(s) given that preregistrations and prespecified analysis protocols were rare” and they noted that “it remains unknown to what extent the present results are affected by publication bias”. In our re-analysis, we demonstrate that publication bias exaggerated the evidence in favor of SC-BCT to such a degree that once this bias is properly adjusted for, the effect disappears entirely. In fact, the data show moderate evidence against the presence of an effect.