Consequences, Norms, and General Action Tendencies: Understanding Individual Differences in Moral Dilemma Judgments

A few years before the Covid-19 pandemic killed more than six million people around the world, an outbreak of the Ebola virus disease in West Africa stirred a heated debate in the United States. The debate was ignited by the case of Dr. Kent Brantly, an American doctor who contracted the Ebola virus in Liberia (Blinder & Grady, 2014). It soon became clear that Dr. Brantly would die if he did not receive advanced medical treatment in his home country, but returning him involved a risk of causing an Ebola outbreak in the United States. In the weeks before Dr. Brantly was returned and cured, some people claimed a moral duty to save Dr. Brantly’s life by returning him to the United States for treatment; others argued that it would be better to let him die in Liberia to avoid the potential death of a larger number of people. The two conflicting views in this debate illustrate two philosophical ideas about morality. From a deontological view, the moral status of a behavioral option depends on its consistency with moral norms. This view is reflected in the argument that returning Dr. Brantly to the United States is morally right, because it conforms to a moral duty to save his life. In contrast, from a utilitarian view, the moral status of a behavioral option depends on its consequences for the greater good. This view is reflected in the argument that not returning Dr. Brantly to the United States is morally right, because it prevents the potential death of a larger number of people. Inspired by the distinction between deontology and utilitarianism, a substantial amount of research has investigated people’s responses to moral dilemmas that pit one philosophical idea against the other (for a review, see Bartels, Bauman, Cushman, Pizarro, & McGraw, 2015). In addition to identifying various contextual factors that influence people’s preference for utilitarian versus deontological judgments (e.g., Suter & Hertwig, 2011; Valdesolo & DeSteno, 2006), this research revealed a wide range of individual-difference variables that are systematically related to moral dilemma judgments (e.g., Gleichgerrcht & Young, 2013; Patil, 2015; Moore, Stevens, & Conway, 2011; Van den Bos, Müller, & Damen, 2011). The latter findings suggest that conflicting views in societal debates about the right course of action in real-world dilemmas (e.g., the debate about Dr. Brantly’s return for medical treatment) may reflect deeper psychological differences between people. In the current chapter, we illustrate the value of a mathematical modeling approach in understanding individual differences in moral dilemma judgments. Toward this end, we first explain the traditional approach to studying moral dilemma judgments and its limitations. We then describe the CNI model of moral decision-making (Gawronski, Armstrong, Conway, Friesdorf, & Hütter, 2017), which quantifies three determinants of moral dilemma judgments: (1) sensitivity to consequences, (2) sensitivity to moral norms, and (3) general preference for inaction versus action. In the remainder of the chapter, we review research that has used the CNI model to investigate the nature of individual differences in moral dilemma judgments. Our central argument is that, by identifying individual differences along the three dimensions, research using the CNI model provides more nuanced insights into the roots of societal controversies about the right course of action in real-world dilemmas.