Odontocetes (‘Toothed Whales’): Cognitive Science and Moral Standing – Are Dolphins Persons?

Odontocetes, or ‘toothed whales’, have a complex brain structure and possess rationality, self-awareness, sociability and culture. Cognitive science and modern theories of personhood challenge the notion that humans alone are moral persons. This paper reviews evidence from the cognitive science literature relevant to moral personhood in bottlenose dolphins, orcas, and beluga whales. It applies theories of personhood of Peter Singer, David DeGrazia, and Steven Wise, and finds that odontocetes fulfil criteria to be granted at least borderline personhood. The legal implications of attributing personhood to dolphins remains uncertain. Recognition of dolphin personhood may lead to fundamental legal rights against capture, captivity, and killing; alternatively, the courts may continue to restrict legal personhood and associated protections to human beings. Finally, despite the major influence of personhood on morality and law in the West, the biologically more widespread quality of sentience is sufficient for greater moral considerability and legal protections for nonhuman species.