Key Social Norms Take-aways This research underscores that interventions solely focused on boosting girls’ agency or spreading legal awareness are unlikely to substantially reduce child marriage rates. Instead, changing community-level social norms — especially caregivers’ and community leaders’ attitudes toward the acceptability of early marriage — and expanding girls’ real-life opportunities, particularly in education, are critical. Effective interventions must address the structural and social pressures that make marriage an appealing or necessary option, even for girls who are aware of and have legal rights to delay marriage.

Objectives This study set out to investigate what drives child marriage among girls in rural Malawi, a country with persistently high rates of child marriage despite legal prohibitions. The researchers aimed to identify which factors — including poverty, education, social norms, legal awareness, and girls’ own agency — significantly predict the likelihood of marrying before age 18.

Methods The study used prospective longitudinal data from the Malawi Longitudinal Study of Families and Health, focusing on a cohort of 806 adolescent girls surveyed between 2017–2018 and 2021. Researchers employed Cox proportional hazards models to assess the impact of various hypothesized drivers on child marriage risk, including school progression, household economic shocks, perceptions of community norms, attitudes about marriage, knowledge of the law, and reported agency over marriage decisions.

Results About 26% of girls in the sample married before age 18. The strongest predictors of child marriage were being behind in school and caregivers’ perceptions of community disapproval of early marriage, with girls lagging in school facing a 15% higher risk per grade missed and girls whose caregivers perceived community disapproval having 40% lower risk. Surprisingly, girls who knew that early marriage was illegal were twice as likely to marry early. Other factors like poverty, wealth, or girls’ reported agency were not significant predictors.

Conclusions The study concludes that child marriage persists in this setting not due to ignorance of the law or lack of agency but because of perceived social norms and limited educational opportunities. Despite widespread knowledge of the legal minimum marriage age and apparent decision-making autonomy among girls, early marriage remains common.