Managerial oversight is strengthened and firms' strategic performance improved when boards are gender-diverse. Yet the rate of women's appointment to corporate boards is decelerating. This study proposes an explanation for the unexpected attenuation rooted in social movement dynamics, particularly cross-movement influences originating from the contemporary governance reform movement. Seeking to alleviate managerialist tendencies, the governance reform movement has compelled major changes to board structure, composition, and activity, as well as the broader logic surrounding corporate boards. By definition, social movements' cognitive and structural advances manifest “spillover” effects – unintentional impacts affecting the opportunity structure, and ultimately progress, of neighboring campaigns. Drawing on social movement theory, a conceptual model is outlined explicating the mechanisms by which governance reform's broad enactments have incidentally impeded board gender diversity's advance. Theoretically-grounded strategies for reversing those effects are also outlined and the study closes with a discussion of implications for research, practice, and policy.

当董事会具有性别差异时，将加强管理监督，并改善公司的战略绩效。然而，女性进入公司董事会的比例正在下降。这项研究提出了对源自社会运动动力学的意外衰减的解释，尤其是源于当代治理改革运动的交叉运动影响。为了减轻管理者的倾向，治理改革运动迫使董事会结构，组成和活动以及围绕公司董事会的更广泛逻辑发生了重大变化。根据定义，社会运动的认知和结构进步表现出“溢出”效应，即无意的影响，影响了邻近运动的机会结构，并最终发展。借鉴社会运动理论，概述了概念模型，阐明了治理改革广泛颁布的机制偶然地阻碍了董事会性别多元化的发展。还概述了用于逆转这些影响的理论基础策略，并且在研究结束时讨论了对研究，实践和政策的影响。