Knowledge creation increasingly requires experts from diverse domains to collaborate in teams, yet the effect of expertise diversity on team knowledge creation is inconclusive. We focus on task uncertainty and informal leadership hierarchies—the disparity in team members’ engagement in leadership activities (task- and relationship-oriented)—to answer the questions when and why expertise diversity may hinder team knowledge creation. We develop a model in which informal leadership hierarchy mediates the conditional indirect effect of the team’s expertise diversity on its knowledge creation under different levels of task uncertainty. We test this moderated mediation model using multi-source data from self-managing project teams comprised of collaborators from a pharmaceutical company and its research partners. We find that when task uncertainty is low, the indirect effect of expertise diversity on team knowledge creation is positive, whereas when task uncertainty is high, it is negative. This conditional indirect effect occurs via task-oriented but not relationship-oriented leadership hierarchy. Our findings provide insights into the mechanisms and boundary conditions for expertise diversity to hinder, rather than facilitate, knowledge creation in collaborations.

知识创造越来越需要来自不同领域的专家在团队中进行协作，但专业知识多样性对团队知识创造的影响尚无定论。我们关注任务的不确定性和非正式的领导层级——团队成员参与领导活动（以任务和关系为导向）的差异——以回答专业知识多样性何时以及为何会阻碍团队知识创造的问题。我们开发了一个模型，其中非正式的领导层级在不同级别的任务不确定性下调节团队专业知识多样性对其知识创造的条件间接影响。我们使用来自制药公司及其研究合作伙伴的合作者组成的自我管理项目团队的多源数据来测试这种有节制的中介模型。我们发现，当任务不确定性较低时，专业多样性对团队知识创造的间接影响是积极的，而当任务不确定性较高时，则是消极的。这种有条件的间接影响是通过面向任务而不是面向关系的领导层级发生的。我们的研究结果提供了对专业多样性阻碍而不是促进合作中知识创造的机制和边界条件的见解。