By Caetano L. B. Franco, Michael G. Sorice, Liliana Sierra Castillo, and Eranga Galappaththi

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Co-management describes communities and government agencies sharing responsibility for setting and enforcing rules. Natural resource co-management is a common approach to governing fisheries, forests, wildlife, and water. In many places, people comply with rules that emerge from co-management even when formal enforcement is limited. One reason is social norms: the unwritten expectations about what people usually do and what others think they should do.

We reviewed 46 empirical studies (1990–2022) to understand how people define, measure, and link social norms to rule compliance in co-management. We found that scholars widely discuss social norms, but often do not clearly explain the concept. Only 20% of studies provided an explicit definition, and those definitions varied substantially across disciplines. Many studies used the terms descriptive norms (“what people do”) and injunctive norms (“what people believe others expect”), but researchers frequently measured these ideas in broad or inconsistent ways. In particular, many papers did not specify the behavioral pathway that connects norms to compliance—such as whose opinions matter, what sanctions exist, or whether people comply only if they believe others are also complying.

Despite these limitations, the evidence points to a consistent pattern: compliance tends to be higher when resource users believe that others are complying and when they anticipate social disapproval for breaking rules. Normative influence is often stronger when peer monitoring, legitimate local leadership, and shared perceptions of resource scarcity support the norms. However, norms do not always support conservation goals. In some contexts, group expectations can tolerate or even encourage rule-breaking, showing that norms are highly context-dependent.

To improve how scholars use social norms in co-management research and practice, we clarify key distinctions among types of norms and align common indicators with behavioral theory (including components such as expectations, reference groups, sanctions, and conditional cooperation). A clearer understanding of how norms operate across individual expectations and collective institutions can help explain compliance beyond formal enforcement and support more adaptive, legitimate, and equitable conservation strategies.