Harmful gender and social norms prescribe divergent opportunities for girls and boys and drive child marriage. This systematic review examines the scope, range and effectiveness of interventions to change social norms and delay child marriage.

We systematically assess the contributions made by interventions that work to shift norms to prevent child marriage or to limit its harmful consequences. Our analysis classifies each study’s quality in evaluation and implementation design regarding shifting norms.

We conducted a search of electronic databases (PubMed, PsycINFO, Embase, CINAHL Plus, Popline, Web of Science and Cochrane Library) and grey literature (targeted hand-searches of 15 key organisations and Google Scholar).

Included interventions sought to change norms related to child marriage, were evaluated in experimental or quasi-experimental evaluations, collected data on age at marriage and norms/attitudes, and were published in English from January 2000 to September 2021.

We used a standardised form to extract data from all eligible studies, and double-screened to validate coding and reporting. We classified the studies by low, medium and high quality for evaluation and risk of bias, and separately by the extent to which they addressed social norms.

Our assessment of the 12 eligible studies identified revealed little evidence of a systematic relationship between social norms related to marriage and changes in child marriage behaviours. We found stronger evidence of programme effect on child marriage outcomes than on social norms, though only a minority of studies found an effect for either. Studies that appeared effective in changing child marriage norms varied greatly in scale and extent of programming, and few attempted to identify the appropriate reference groups for measuring social norms.

The studies evaluated by our review provide only weak evidence on the impact of interventions on norms, and on the link between shifts in norms and marriage behaviour.