In 14 studies, we tested whether political conservatives’ stronger free will beliefs were linked to stronger and broader tendencies to moralize and, thus, a greater motivation to assign blame. In Study 1 (meta-analysis of 5 studies, n = 308,499) we show that conservatives have stronger tendencies to moralize than liberals, even for moralization measures containing zero political content (e.g., moral badness ratings of faces and personality traits). In Study 2, we show that conservatives report higher free will belief, and this is statistically mediated by the belief that people should be held morally responsible for their bad behavior (n = 14,707). In Study 3, we show that political conservatism is associated with higher attributions of free will for specific events. Turning to experimental manipulations to test our hypotheses, we show the following: when conservatives and liberals see an action as equally wrong there is no difference in free will attributions (Study 4); when conservatives see an action as less wrong than liberals, they attribute less free will (Study 5); and specific perceptions of wrongness account for the relation between political ideology and free will attributions (Study 6a and 6b). Finally, we show that political conservatives and liberals even differentially attribute free will for the same action depending on who performed it (Studies 7a–d). These results are consistent with our theory that political differences in free will belief are at least partly explicable by conservatives’ tendency to moralize, which strengthens motivation to justify blame with stronger belief in free will and personal accountability.

Sacrificial moral dilemmas are widely used to investigate when, how, and why people make judgments that are consistent with utilitarianism. But to what extent can responses to sacrificial dilemmas shed light on utilitarian decision making? We consider two key questions: First, how meaningful is the relationship between responses to sacrificial dilemmas and what is distinctive of a utilitarian approach to morality? Second, to what extent do findings about sacrificial dilemmas generalise to other moral contexts where there is tension between utilitarianism and common-sense intuitions? We argue that sacrificial dilemmas only capture one point of conflict between utilitarianism and common-sense morality, and new paradigms are needed to investigate other key aspects of utilitarianism, such as its radical impartiality.

We introduce and investigate the philosophical concept of ‘speciesism’ —the assignment of different moral worth based on species membership —as a psychological construct. In five studies, using both general population samples online and student samples, we show that speciesism is a measurable, stable construct with high interpersonal differences, that goes along with a cluster of other forms of prejudice, and is able to predict real-world decision-making and behavior. In Study 1 we present the development and empirical validation of a theoretically driven Speciesism Scale, which captures individual differences in speciesist attitudes. In Study 2, we show high test-retest reliability of the scale over a period of four weeks, suggesting that speciesism is stable over time. In Study 3, we present positive correlations between speciesism and prejudicial attitudes such as racism, sexism, homophobia, along with ideological constructs associated with prejudice such as social dominance orientation, system justification, and right-wing authoritarianism. These results suggest that similar mechanisms might underlie both speciesism and other well-researched forms of prejudice. Finally, in Studies 4 and 5, we demonstrate that speciesism is able to predict prosociality towards animals (both in the context of charitable donations and time investment) and behavioral food choices above and beyond existing related constructs. Importantly, our studies show that people morally value individuals of certain species less than others even when beliefs about intelligence and sentience are accounted for. We conclude by discussing the implications of a psychological study of speciesism for the psychology of human-animal relationships

Recent research has relied on trolley-type sacrificial moral dilemmas to study utilitarian versus nonutilitarian modes of moral decision-making. This research has generated important insights into people’s attitudes toward instrumental harm-that is, the sacrifice of an individual to save a greater number. But this approach also has serious limitations. Most notably, it ignores the positive, altruistic core of utilitarianism, which is characterized by impartial concern for the well-being of everyone, whether near or far. Here, we develop, refine, and validate a new scale-the Oxford Utilitarianism Scale-to dissociate individual differences in the ‘negative’ (permissive attitude toward instrumental harm) and ‘positive’ (impartial concern for the greater good) dimensions of utilitarian thinking as manifested in the general population. We show that these are two independent dimensions of proto-utilitarian tendencies in the lay population, each exhibiting a distinct psychological profile. Empathic concern, identification with the whole of humanity, and concern for future generations were positively associated with impartial beneficence but negatively associated with instrumental harm; and although instrumental harm was associated with subclinical psychopathy, impartial beneficence was associated with higher religiosity. Importantly, although these two dimensions were independent in the lay population, they were closely associated in a sample of moral philosophers. Acknowledging this dissociation between the instrumental harm and impartial beneficence components of utilitarian thinking in ordinary people can clarify existing debates about the nature of moral psychology and its relation to moral philosophy as well as generate fruitful avenues for further research.