By drawing attention to task conflict resolution and reporting on its empirical relations with key team variables, the present study offers a new perspective on team effectiveness. Specifically, we examined how three "dark" personality traits (Manipulativeness, Narcissism, and Secondary Psychopathy) relate to team conflict resolution, team innovation, and team task performance in student engineering design project teams. Interestingly, results indicate that mean team levels of Secondary Psychopathy is the most important predictor, and task conflict resolution is a mediator linking mean Secondary Psychopathy to team task performance. Furthermore, the prediction of team performance by Secondary Psychopathy is as strong as is any of the "Big 5" personality variables investigated in meta-analyses.