Actions that financially benefit one person may present risk to another person. For example, the payment incentives of portfolio managers and investors are often asymmetrical such that actions that benefit a portfolio manager can pose financial risk to clients. Despite the presence and potential harm of these asymmetries, few have addressed the question of who exploits these asymmetries and how to mitigate potential harm. Our study examined the effect of selfish personality traits (the Dark Triad) and interpersonal bonding on decision-making (...) for the self, another person, and another person with under reward asymmetry present. Results demonstrated that individuals higher in narcissism and psychopathy made risky decisions for themselves. However, when reward asymmetries were present, all three Dark Triad traits were associated with making riskier decisions for another person in order to benefit the self. There was also a significant interaction between interpersonal closeness generated through bonding and psychopathy such that bonding made the decision-making processes of those high in psychopathy less risky for others. These findings have implications for how different individuals with different relationships make self and other-based financial decisions, and how those decisions change when rewards are asymmetrical. (shrink)