We develop and test predictions about how demographic differences influence dyadic deference in multidisciplinary research teams and how differential patterns of dyadic deference emerge to shape team-level effectiveness. We propose a dual pathway model, which recognizes that two distinct mechanisms - task contributions and social affinity - account for how team members' demographic attributes contribute to deference. And, we propose that the extent to which these different mechanisms are prevalent in a team has implications for the team's research productivity; deference based on social affinity detracts from and deference based on task contributions enhances productivity. Using longitudinal data from a sample of 55 multidisciplinary research teams comprising 619 scientists, we found general support for our conceptual model. Our findings underscore the importance of accounting for multiple interpersonal mechanisms to understand the complex, multilevel nature of deference in teams.