Invertebrate animals are frequently lumped into a single category and denied welfare protections despite their considerable cognitive, behavioral, and evolutionary diversity. Some ethical and policy inroads have been made for cephalopod molluscs and crustaceans, but the vast majority of arthropods, including the insects, remain excluded from moral consideration. We argue that this exclusion is unwarranted given the existing evidence and plausible concepts of moral standing. Yet anachronistic, value-laden readings of evolution still view invertebrates as lower in the scala naturae. There persists the a priori assumption that small brains are unlikely to support cognition or sentience, despite the growing evidence that they have converged on cognitive functions comparable to those of vertebrates. Cognitive-affective biases influence moral judgments and the attribution of mental states. Scientific uncertainty and moral risk are not appropriately balanced. These factors shape moral attitudes toward basal vertebrates too, but they are particularly acute in the arthropod context. Moral consistency dictates that the same standards of evidence and risk management that justify policy protections for vertebrates also support extending moral consideration to certain invertebrates. We also show how moving beyond a vertebrate-centered concept of welfare can help clarify foundational moral concepts in their own right.

Author Biography

Irina Mikhalevich, Assistant Professor of Philosophy, Rochester Institute of Technology, specializes in conceptual and methodological problems in comparative cognition science and their implications for the treatment of nonhuman animals. Website

Russell Powell, Associate Professor of Philosophy, Boston University, specializes in philosophical problems in evolutionary biology and bioethics. Website



Article Thread

Mikhalevich, Irina and Powell, Russell (2020) Minds without spines: Evolutionarily inclusive animal ethics. Animal Sentience 29(1)

Levy, Neil (2020) It might not matter very much whether insects are conscious. Animal Sentience 29(2)

Figdor, Carrie (2020) Relationship between cognition and moral status needs overhaul. Animal Sentience 29(3)

Browning, Heather and Veit, Walter (2020) Improving invertebrate welfare. Animal Sentience 29(4)

Vonk, Jennifer (2020) No room for speciesism in welfare considerations. Animal Sentience 29(5)

Cammaerts, Marie-Claire (2020) Invertebrates should be given ethical consideration. Animal Sentience 29(6)

Soryl, Asher (2020) Invertebrate welfare in the wild. Animal Sentience 29(7)

Monsó, Susana and Osuna-Mascaró, Antonio J. (2020) Problems with basing insect ethics on individuals’ welfare. Animal Sentience 29(8)

Balcombe, Jonathan (2020) Intuition and the invertebrate dogma. Animal Sentience 29(9)

Elwood, Robert W. (2020) Do arthropods respond to noxious stimuli purely by reflex?. Animal Sentience 29(10)

Zentall, Thomas R. (2020) Cognition, movement and morality. Animal Sentience 29(11)

Lockwood, Jeffrey A. (2020) Virtue ethics and the likelihood of invertebrate suffering. Animal Sentience 29(12)

Veit, Walter and Huebner, Bryce (2020) Drawing the boundaries of animal sentience. Animal Sentience 29(13)

Mallatt, Jon and Feinberg, Todd E. (2020) Sentience in evolutionary context. Animal Sentience 29(14)

DeGrazia, David (2020) On the possibility of invertebrate sentience. Animal Sentience 29(15)

Woodruff, Michael L. (2020) Whether invertebrates are sentient matters to bioethics and science policy. Animal Sentience 29(16)

Baracchi, David and Baciadonna, Luigi (2020) Insect sentience and the rise of a new inclusive ethics. Animal Sentience 29(18)

Marino, Lori (2020) Sentience in all organisms with centralized nervous systems. Animal Sentience 29(19)

Lee, Andrew Y. (2020) Does sentience come in degrees?. Animal Sentience 29(20)