Organizational citizenship behavior (OCB) is essential to the smooth functioning of organizations. A vast amount of research examining OCB has established the benefits of such behavior to businesses. In addition, individual- and organizational-level antecedents of citizenship behavior have been widely studied and well established. However, a sound assessment of OCB, which acknowledges the true social cognitive nature of the phenomenon, is yet to be developed. The purpose of this study is two-fold: First, this study seeks to develop a reliable, accurate measure of OCB. Second, this study utilizes the newly developed measure to determine how personal characteristics and situational influences interact to produce helping behavior. More specifically, this study explores how equity sensitivity, locus of control, self-esteem, and affectivity determine whether an employee engages in helping behavior. Further, the current study examines whether situation cue strength moderates the relationship between the aforementioned personality characteristics and an employee's decision to engage in helping behavior.