Perhaps paradoxically, the rise in inequality has not been accompanied by increased public support for redistribution in many societies. This contradicts the traditional political economy prediction that a poorer majority demands more redistribution. The present study proposes a behavioral mechanism behind this paradox: when inequality is high, the greater rewards at the top motivate people to hold optimistic beliefs about their economic prospects. We conduct an online experiment where participants are randomly assigned to societies with different levels of initial inequality, form beliefs about their chances of reaching the top position, and make consequential decisions about income redistribution. Our findings reveal four key results. First, participants exposed to high initial inequality display significantly higher confidence in reaching the top compared to those in low inequality. Second, higher confidence strongly correlates with lower support for redistribution. Third, combining these channels, participants initially experiencing high inequality ultimately prefer significantly more unequal income distributions. Fourth, accurate feedback about actual chances of reaching the top does not eliminate inequality-induced overconfidence or inequality acceptance. Our results highlight motivated overconfidence as a novel behavioral mechanism that helps explain how inequality can be self-sustaining through its distortionary effects on beliefs and redistribution preferences.