Recent research suggests that agreeable individuals experience greater financial hardship than their less agreeable peers. We explore the psychological mechanisms underlying this relationship and provide evidence that it is driven by agreeable individuals considering money to be less important, but not (as previously suggested) by agreeable individuals pursuing more cooperative negotiating styles. Taking an interactionist perspective, we further hypothesize that placing little importance on money-a risk factor for money mismanagement-is more detrimental to the financial health of those agreeable individuals who lack the economic means to compensate for their predisposition. Supporting this proposition, we show that agreeableness is more strongly (and sometimes exclusively) related to financial hardship among low-income individuals. We present evidence from diverse data sources, including 2 online panels (n1 = 636, n2 = 3,155), a nationally representative survey (n3 = 4,170), objective bank account data (n4 = 549), a longitudinal cohort study (n5 = 2,429), and geographically aggregated insolvency and personality measures (n6 = 332,951, n7 = 2,468,897). (PsycINFO Database Record (c) 2020 APA, all rights reserved).