How In-Group Bias Shapes Decision-Making on the U.S. Courts of Appeals

Scholars increasingly recognize that identity is a critical component of judicial decision-making. On the appellate courts, this work primarily examines the impact of judge identity. However, research demonstrates that litigant identity is likewise consequential for outcomes. We contend that judge and litigant identity must be considered in tandem to arrive at a more complete account of appellate court decision-making. Drawing on social psychology, we explore how judge and litigant gender jointly condition outcomes across nearly four decades of U.S. Courts of Appeals decisions. Our findings reveal important asymmetries across issue areas that diverge from trial court scholarship. Female judges are less likely to rule for female appellants in criminal cases at low levels of bench diversity. Male judges show no such effect. In civil rights cases, judges favor female appellants over male appellants at low levels of bench diversity. This gap narrows as diversity increases, where judges of both genders are more likely to support male appellants. These asymmetries underscore the centrality of context in judicial decision-making and add nuance to scholarship exploring how immutable characteristics can shape judicial outcomes.