A long-standing prejudice based on feelings of disgust and speciesism has excluded non-vertebrate animals like octopuses and insects from moral consideration. But invertebrate brains comprise upwards of 99% of the brains on the planet, argue two philosophers in the journal Animal Sentience, and we need to treat them accordingly. It is time to end the “vertebrate dogma”.
Their contentions are supported by a good number of comments from other academics in a commentary section of the journal.
Part of the problem is that anachronistic views of evolution, which regard invertebrates as “lower” beings, continue to influence public policy and common morality, contend Irina Mikhalevich, of Rochester Institute of Technology, and Russell Powell, of, Boston University. But studies of invertebrate behaviour, especially of bees, suggest that they may have a rich inner life. They may deserve moral status.
“Honeybees can be taught addition and subtraction procedures, appear to have the concept of ‘zero’ and can learn to attend to global or local features of objects ... Bees and wasps can recognize human faces... One study suggests that ants can pass the mirror self-recognition test which human infants only pass at around 20 months of age. There is even tantalizing evidence of causal reasoning and means-end rationality in bees and transitive inference in paper wasps.”
They may even have feelings. “For example, bumblebees tend to interpret ambiguous stimuli more optimistically after exposure to a pleasant stimulus, just as humans tend to do when they are happy or calm. Conversely, vigorously shaking bees appears to induce a pessimistic bias in odor discrimination tests.”
Obviously, the evidence that non-vertebrates have inner states is controversial and ambiguous, but isn’t it better for policy-makers to play it safe, the authors ask. “If the costs of falsely attributing sentience to animals are minor while the costs of false negatives are high (because, for instance, they result in a great deal of unnecessary suffering), then erring on the side of false positives is prima facie ethically preferable.”
But wouldn’t including invertebrates in the moral community impose ridiculous demands upon humans? Mikhalevich and Powell are adamant. “The fact that living up to our moral obligations is hard is a patently inadequate reason for failing to meet those obligations.” Besides, this does not mean that we must give equal moral consideration to all beings; it would probably be proportionate to their sentience.
There would be sticky situations, they acknowledge. “Whether harm to a small number of vertebrate subjects is morally preferable to harm to a large number of invertebrate subjects is unclear. But such questions should be resolved through an analysis of interest conflicts, not by according some legitimate interests no weight at all.”
Michael Cook is editor of BioEdge
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