Impartiality preferences in sacrificial moral dilemmas involving autonomous vehicles

The development of autonomous vehicles has stimulated research into preferences in sacrificial moral dilemmas. Studies such as the Moral Machine Experiment, which has attracted enormous attention in both philosophy and psychology, have been criticized for an important methodological flaw: forcing participants to choose between two options, like killing a man or a woman. It has been shown that many people actually prefer a third option, namely treating people ‘equally’. While this is an important improvement, we argue that ‘equal’ treatment can be understood in different ways. Instead of ‘equality’, we propose to use the concept of impartiality and argue that impartiality needs to be complemented with action-guiding decision rules. To support this conceptual point, we conducted a vignette study. Our results suggest that impartiality is indeed the main preference and that the most attractive decision rule to complement impartiality is not random choice, as many papers suggest, but inaction.