This chapter provides an overview of the role of incentivised decision-making experiments in studying political ideology. We first discuss experiments that conceptualise political ideology along a unidimensional liberal-conservative spectrum and explore whether there are systematic behavioural differences between liberals and conservatives. While recent studies find that liberals display more pro-social tendencies, many other studies find that liberals and conservatives display similar levels of pro-social, ingroup-biased, normative, and punitive behaviour. We then present an overview of experiments that study two-dimensional political ideology as embodied in the concepts of economic conservatism (as opposed to economic progressivism; usually measured with the Social Dominance Orientation scale) and social conservatism (as opposed to social progressivism; usually measured with the Right-Wing Authoritarianism scale). We demonstrate that economic conservatives display lower levels of cooperation and universalism, greater tolerance for inequality, and a tendency to harm outgroups. Social conservatives tend to generally engage in group-minded behaviour, including distrusting anonymous strangers, cooperating with ingroup members, following rules, punishing (mainly in the ultimatum game), and sometimes harming outgroups.