Key Social Norms Take-aways This study highlights that community-level social norms around child marriage—specifically, the average perceived appropriate age of marriage and norms around girls’ education and labor—significantly influence individual girls’ marriage expectations and transitions. Norms function both through collective expectations and the behavior of others in the community, reinforcing early marriage in contexts where it is seen as the norm. The findings reinforce the importance of addressing community-level beliefs and practices, rather than targeting only individual-level change, to effectively delay child marriage.

Objectives The study aimed to identify the role of community social norms in shaping girls’ expectations about marriage timing and their actual entry into marriage across four low- and middle-income countries: Ethiopia, India (Andhra Pradesh and Telangana), Peru, and Vietnam.

Methods Using longitudinal survey data from the Young Lives study, the authors conducted econometric analysis on a sample of 9,000 adolescents to estimate the influence of community-level norms on girls’ marriage expectations at age 15 and actual marriage transitions by age 22. Community norms were constructed from aggregated peer responses on expected age of marriage, education, and labor participation. The study controlled for individual and household characteristics, using probit models to assess the association between community norms and individual outcomes.

Results Community-level norms regarding marriage and girls’ roles significantly predicted both expectations and actual marriage timing. In communities where peers expected girls to marry younger, individual girls were more likely to expect early marriage themselves and were more likely to be married by age 22. Norms around girls’ education and work were also influential; in communities where girls were expected to work or pursue education longer, individual marriage was delayed. The influence of norms remained significant even when controlling for individual and household variables, suggesting that community expectations have an independent effect on shaping girls’ life trajectories.

Conclusions The study concludes that community social norms are a powerful determinant of adolescent girls’ marriage timing and expectations. Efforts to reduce child marriage must therefore go beyond targeting individual behavior change and instead engage with collective beliefs and behaviors at the community level. Social norms operate through shared expectations and observed practices, reinforcing each other over time. Effective child marriage prevention strategies should integrate norm-shifting approaches that address these wider community dynamics.