The purpose of this study was to aggregate the findings of three distinct areas of research into one model of team effectiveness. Specifically, it was hypothesized that, in accordance with prior research findings, aspects of personality related to social intelligence would predict informal leadership emergence. Furthermore, it was predicted that multiple leaders within a team would positively influence that team's subsequent level of performance, through the mediating influence of team mental model similarity and team mental model accuracy. Participants included 40 computer science and engineering teams, who completed their surveys at time one, whereas performance criterion measures were collected at time two. Contrary to prediction, results indicated that social intelligence was not a significant predictor of leadership emergence, and leadership dispersion did not directly impact team performance. However, leadership dispersion positively impacted team mental model accuracy, and team mental model accuracy and similarity positively affected subsequent team performance, as hypothesized. Therefore, the current study provides partial support for a model of team performance that takes into account multiple leadership within teams and its positive influence on the dissemination and development of important, task-related knowledge structures among team members.