While psychologists and political scientists have long investigated issues of interest to philosophers, the development of political experimental philosophy has remained limited. This is surprising, since political philosophers commonly acknowledge the relevance of empirical data to normative theorizing. This chapter illustrates the importance of empirical data by outlining recent developments in three domains related to theories of justice where empirical results reinforce or endanger popular philosophical theories. The first showcase concerns the boundaries of fairness. While both libertarians and social egalitarians have united in rejecting the concept of natural injustice, it is shown that people do consider that unpreventable natural inequalities can be described as unfair. Second, this chapter takes the example of impartiality devices, such as the veil of ignorance, to show that such devices are efficient at shifting people’s intuitions in a more impartial manner. Third, empirical data on fairness intuitions are reviewed to show that people conform to a pluralist theory of justice by valuing desert, needs-satisfaction, and equality. However, distribution according to desert enjoys a privileged position. The centrality of desert leads to dilemmas for mainstream egalitarian theorists, as theories that do not recognize the value of desert could fail to find support or legitimacy within the population.