This dissertation focuses on examining social-psychological processes embedded in the boardsÕ internal and external environments. Although boards of directors are commonly seen as the formal link between the firmsÕ shareholders and top management, a growing line of literature suggests boards as groups with each director bringing his or her personality and individual experiences into the boardroom. Accordingly, in addition to the directorsÕ professional-related knowledge and experiences, social-psychological processes _ related to the exchange of information, group participation, and interaction _ are critical determinants of board effectiveness. Thus, the consideration of such processes within the upper echelons of firms may help to explain in more detail why some boards are in a better position than others to effectively fulfill their roles and, thereby, to ensure their firmsÕ long-term success.