Many of our everyday life experiences suggest that humans are social individuals who care about themselves and others. Yet, for a long time, the economic discipline has focused on modeling the purely self-interested “homo economicus”. In this review, we summarize the extensive experimental literature on deviations from such purely self-interested behavior, with a particular focus on attitudes toward inequality and fairness. This literature shows that many individuals are willing to forgo their own economic gain for a fairer distribution of resources. We further illustrate empirical evidence showing that people differ in what they consider to be fair, and how these fairness views vary within and across countries.