Artificial intelligence and robotics are rapidly advancing. Humans are increasingly often affected by autonomous machines making choices with moral repercussions. At the same time, classical research in robotics shows that people are adverse to robots that appear eerily human—a phenomenon commonly referred to as the uncanny valley effect. Yet, little is known about how machines’ appearances influence how human evaluate their moral choices. Here we integrate the uncanny valley effect into moral psychology. In two experiments we test whether humans evaluate identical moral choices made by robots differently depending on the robots’ appearance. Participants evaluated either deontological (“rule based”) or utilitarian (“consequence based”) moral decisions made by different robots. The results provide first indication that people evaluate moral choices by robots that resemble humans as less moral compared to the same moral choices made by humans or non-human robots: a moral uncanny valley effect. We discuss the implications of our findings for moral psychology, social robotics and AI-safety policy.

人工智能和机器人技术正在迅速发展。人类越来越多地受到具有道德影响的自主机器的选择的影响。同时，有关机器人技术的经典研究表明，人对看起来像人类的机器人不利-这种现象通常被称为奇异谷效应。然而，对于机器的外观如何影响人类评估其道德选择的方式知之甚少。在这里，我们将不可思议的山谷效应整合到道德心理学中。在两个实验中，我们测试了人类是否根据机器人的外观对机器人做出的相同道德选择进行了不同的评估。参与者评估了由不同机器人做出的道义（基于规则）或功利主义（基于后果）道德决定。该结果首次表明，人们对类似于人类的机器人的道德选择所评估的道德水平要低于人类或非人类机器人做出的相同道德选择：道德异常谷效应。我们讨论了我们的发现对道德心理学，社交机器人和AI安全政策的意义。