The influence of gender diversity on the success of scientific teams is of great interest to academia. However, prior findings remain inconsistent, and most studies operationalize diversity in aggregate terms, overlooking internal role differentiation. This limitation obscures a more nuanced understanding of how gender diversity shapes team impact. In particular, the effect of gender diversity across different team roles remains poorly understood. To this end, we define a scientific team as all coauthors of a paper and measure team impact through five-year citation counts. Using author contribution statements, we classified members into leadership and support roles. Drawing on more than 130,000 papers from PLOS journals, most of which are in biomedical-related disciplines, we employed multivariable regression to examine the association between gender diversity in these roles and team impact. Furthermore, we apply a threshold regression model to investigate how team size moderates this relationship. The results show that (1) the relationship between gender diversity and team impact follows an inverted U-shape for both leadership and support groups; (2) teams with an all-female leadership group and an all-male support group achieve higher impact than other team types. Interestingly, (3) the effect of leadership-group gender diversity is significantly negative for small teams but becomes positive and statistically insignificant in large teams. In contrast, the estimates for support-group gender diversity remain significant and positive, regardless of team size.

翻译：性别多样性对科研团队成功的影响备受学术界关注。然而，现有研究结论尚不一致，且多数研究采用聚合指标度量多样性，忽视了团队内部的角色分化。这一局限阻碍了对性别多样性如何塑造团队影响力更细致入微的理解。特别是，性别多样性在不同团队角色中的影响机制尚不明确。为此，我们将科研团队定义为论文的所有合著者，并通过五年引用量衡量团队影响力。利用作者贡献声明，我们将团队成员划分为领导角色与支持角色。基于PLOS期刊中超过13万篇论文（大部分属于生物医学相关领域），我们采用多变量回归分析检验了这些角色中的性别多样性与团队影响力之间的关联。进一步，我们应用阈值回归模型探究团队规模如何调节这一关系。结果表明：（1）性别多样性与团队影响力之间的关系在领导组和支持组中均呈倒U型；（2）拥有全女性领导组与全男性支持组的团队比其他团队类型获得更高的影响力。有趣的是，（3）领导组性别多样性的影响在小型团队中显著为负，但在大型团队中转为正向且统计上不显著。相比之下，支持组性别多样性的估计值始终显著为正，且不受团队规模影响。