Key Social Norms Take-aways This study highlights the powerful role of collective social norms—especially those related to fertility—in shaping modern contraceptive use among both men and women in Nigeria and Zambia. In both countries, higher community-level fertility norms (i.e., desire for larger families) were consistently associated with lower contraceptive use for both genders. However, gender norms and family planning norms had more mixed and context-specific effects, particularly differing by country and by sex. Notably, community-level norms often mattered more than individual attitudes, suggesting the importance of targeting collective expectations when designing reproductive health interventions.

Objectives To examine how collective fertility, gender, and family planning norms at the community level are associated with individual modern contraceptive use among men and women in Nigeria and Zambia.

Methods The study uses 2018 Demographic and Health Survey (DHS) data from Nigeria and Zambia, applying multilevel logistic regression models to analyze data from over 43,000 men and women living in 1,934 communities. Modern contraceptive use was the primary outcome. Collective norms were constructed by aggregating individual responses within clusters (communities) to reflect average attitudes and behaviors related to fertility preferences, gender roles (via SWPER index), and family planning decision-making. Separate models were run for men and women in each country, controlling for individual- and community-level covariates.

Results Across both countries, higher community-level ideal number of children was significantly and consistently associated with lower use of modern contraception for both men and women. In Nigeria, women’s contraceptive use was positively associated with community gender norms supporting decision-making and non-acceptance of domestic violence, while in Zambia, these same gender empowerment measures were inconsistently or negatively associated. Men’s contraceptive use was also affected by different norms than women’s, including unexpected positive associations with norms suggesting promiscuity linked to contraceptive use. Community-level effects explained more variation in contraceptive use among men than women.

Conclusions Community-level fertility norms are key predictors of contraceptive behavior for both men and women, but other social norms have more complex, gender- and context-specific influences. Programs should tailor interventions to account for these differences and move beyond individual-level change to address broader social environments that shape reproductive decision-making.