AbstractThis paper investigates the way different sides of grit in uence behavior. We show that, in addition to grit's well-known upside in achieving economic success, it has a potential downside too. Specifically, we conduct an experiment using a game of luck and elicit each individual's intended plan of action and compare it to actual choice. We find that grittier individuals have a higher tendency to overplay. We then split grit into two new categories, tenacity and diligence, and obtain that tenacity alone captures the difficulty in respecting ex-ante preferences when this means accepting defeat. Both components of grit correlate with lower self-reported procrastination problems and higher self-esteem, with diligence being the more beneficial trait. Overall, the results indicate that diligence has a clear upside while tenacity has both the upside of not giving up and the downside of not letting go.