Will Human-Animal Chimeras Cause Moral Confusion? Exploring Public Attitudes

Recent medical research involving human-monkey chimeras, human brain organoids in rats, and the transplantation of a gene-edited pig heart and gene-edited pig kidneys in living human beings have intensified the debate about whether we should create human-animal chimeras for biomedical purposes and, if so, how we should treat them. Influential views in the debate frequently appeal to assumptions regarding how people will react to such chimeras. It has, for example, been argued that the most important objection against creating such chimeras is that this will result in inexorable moral confusion about species boundaries and will, as a result, threaten the social order. But is this indeed the case? We conducted three empirical studies to examine laypeople's views on the creation and treatment of various types of human-animal chimeras. Our studies indicate that laypeople find typical cases of xenotransplantation (i.e., the transplantation of an animal organ into a human patient) morally unproblematic. They assign the same moral status to humans with animal organs as to non-chimeric humans. By contrast, they sometimes (but not always) assign slightly higher moral status to animals with human organs than to non-chimeric animals. Overall, however, there is little indication of chimera technology blurring the line between humans and animals, and thus of the technology causing moral confusion.