The prevalence of shareholder activism has resulted in the placement of activist appointed directors to the boards of firms. Extant work examining this phenomenon has taken a rational approach in examining how the placements of such ‘activist directors’ (ADs) bring about activist change. As a result, much remains unknown as to the behavioral implications associated with their placement on boards, and how this may serve to influence firm change. Specifically, the successful placement of activist directors is expected to elicit behavioral responses from incumbent board members, who may then develop a resistance to change due to perceived issues stemming from such director placement. Because boards often perform as a team in exercising their powers collectively, such resistance may then serve to impact activist change in a firm. To date, no study has examined the behavioral implications surrounding how AD placement may influence a firm’s strategic change. I address this gap in the current dissertation by developing and testing a conceptual model which attempts to explain the governance implications of such director placements. Building upon extant research from the change resistance literature, I posit that the mode of entry and prior ties associated with ADs may serve to impact a board’s willingness to accept and enact their proposals. To that end, I also examine as to how behavioral factors involving similarity between activist and incumbent directors may serve to lead to change. The validity of the conceptual model developed in this dissertation proposal has been tested using a panel dataset of 815 firms affected by shareholder activism during the years 2010 to 2020. The results provide support for the idea that ADs affect the board decision-making process through influencing incumbent directors’ resistance to change.