Behavioural Markers of Consciousness Shape Moral Status Judgments

Whether an individual is conscious or not has important ethical and legal implications. For example, animal welfare regulations seek to minimize suffering in conscious animals, and AI ethics discussions focus on the possibility of artificial consciousness as a key concern. Critically, consciousness cannot be directly perceived, but must be inferred from external cues such as behaviour and biological makeup. It remains unknown how people form such inferences. In three experiments, 652 English-speaking adults formed beliefs about consciousness based on behaviours that are considered markers of consciousness in the scientific literature. A between-subject staircasing procedure revealed that beliefs about consciousness contribute to moral status, and that such beliefs partly explain the moral significance of biological similarity to humans. Finally, markers of visual awareness contributed more to moral status than markers of self-awareness, despite similar effects on the perception of consciousness. We discuss implications for societal and legal discussions of non-human ethics.