Economic inequality is one of the most pressing issues in many countries, not only in the developing but also in the developed countries. Thus, it has received growing public and scientific attention. Economic inequality is costly; however, people seem prefer somewhat inequality. For example, when asking people about the ideal distribution of wealth in their country, they actually prefer some unequal distributions. People also have policy debates ranging from taxation to welfare that aiming to reduce economic inequality. Why? What mechanisms explain this acceptance and tolerance of economic inequality? Based on the perspective of social psychology, in this review, we suggested a dual pathway model: how people perceive and evaluate economic inequality (i.e., cognitive path), and their anticipated benefits of inequality (i.e., motive path) could explain why they tend to tolerant inequality and to ignore the problems caused by economic inequality. In the cognitive path, first, people often estimate that their societies are far more equal than the actual level of economic inequality. The underestimated perception of (but not actual) inequality could predict more acceptance of economic inequality and less supportive of redistribution. Thus, we suggest that people underestimate the actual levels of wealth and income inequality, and this “underestimated inequality” can be regarded as a mechanism for why people are somewhat tolerant of economic inequality. Second, people tend to believe that inequality is fair, which comes from (a) a fair system and (b) individual differences in ability, personal effort, and success. Such beliefs would lead people to be insensitive to economic inequality, to consider current economic distribution as fair, and thus in turn to accept rather than oppose inequality. Indeed, evidence suggests that people are more likely to accept and maintain economic inequality when they have a tendency to legitimate the social system or when they attribute the inequality to personal characteristics, such as abilities, effort, or person choices. In the motive path, we suggested that people tend to anticipate that they would have more benefits from economic inequality, which leads them to be more likely to tolerant economic inequality. For example, evidence shows that people are more willing to tolerate inequality and to oppose to redistribution when they anticipate to have greater upward rather than downward income mobility for themselves and their children. Also, research on social class indicates that occupying advantageous positions on hierarchies related to resources, higher social class individuals tend to be less sensitive towards inequality and be more favorable to their own interests. Given this evidence, we suggest that the tolerance of economic inequality might be also motivated by selfish-related motivations. Before closing, we should briefly outline some potential avenues for future research. First, we should clarify whether people really concern about economic inequality rather than unfairness issue, poverty issue, or social conflicts stems from the inequality. Second, we should examine the relations between the cognitive and motive paths and to understand how these relations influence people’s attitude towards economic inequality. Third, we should explore interventions that would encourage people to support social policy that helps to reduce economic inequality.