The New York Declaration on Animal Consciousness, signed on April 19, 2024 by a diverse group of eminent scientists and philosophers, marks an important acknowledgment of the growing scientific evidence that a wide range of animals, including all vertebrates and many invertebrates, are likely conscious and able to subjectively experience the world.
The declaration highlights that there is strong scientific support for consciousness in mammals and birds, and a “realistic possibility” of consciousness in other vertebrates like reptiles, amphibians and fishes, as well as many invertebrates including octopuses, crabs, shrimps, and insects. Recent studies have revealed:
• Garter snakes recognize their own scent, indicating a degree of self-awareness
• Octopuses avoid pain and seek pain relief, suggesting they have subjective experiences
• Cuttlefish can remember details of specific past events, indicating episodic-like memory
• Bees display behavior consistent with play, a sign of positive emotional states
• Fruit flies have active and quiet sleep patterns that are disrupted by social isolation, paralleling human experiences
Behaviors like learning, planning, problem-solving, and self-recognition provide compelling evidence that invertebrate minds are more complex than commonly assumed. Such cognitive sophistication is not required for consciousness, but its presence is strong evidence of consciousness because, as far as we know, these behaviors require it.
These findings underscore that the ability to suffer and experience wellbeing is likely widespread throughout the animal kingdom. As we have argued in our texts about impartiality and the moral relevance of sentience, subjective experience, not species membership or particular nervous system configurations, is what matters for moral consideration. The declaration makes three key points: 1) There is strong scientific support that mammals and birds are conscious. 2) There is a realistic possibility that all vertebrates and many invertebrates are conscious. 3) Where there is a realistic possibility of consciousness, we have an ethical obligation to consider the welfare risks and interests of those animals as individuals.
This third point is crucial. Absolute certainty about consciousness, even in humans, is not currently possible. But a realistic possibility of sentience is sufficient to warrant serious moral consideration. Our current speciesist attitudes, which discount the experiences of animals and treat them as mere resources, are ethically untenable. An antispeciesist approach, grounded in respect for sentience, means giving moral consideration to all beings that may be capable of suffering and feeling well, regardless of their species, where they live, or when they live.
The inclusion of invertebrates is particularly noteworthy, as they are often neglected in animal welfare considerations despite making up the vast majority of animals on the planet. The majority of animals exploited by humans are invertebrates like crustaceans and insects – hundreds of billions per year – and animal advocates rarely mention them. Even larger numbers of these animals live in the wild, where they face intense challenges like disease, starvation, parasitism, and predation. An antispeciesist ethic implies that we should help them whenever we can, regardless of the source of their suffering. This may be an immense challenge given the scale involved, but we don’t have to solve the whole problem in order to have a big impact. Progress has already been made by processing enormous amounts of data collected by a combination of cameras, microphones, light, and thermal imaging. As we continue to support research to understand and improve their wellbeing, we can avoid contributing to the suffering of animals through exploiting them or harming them as a side effect of our activities.
We must also consider the importance of the future. If humans ever settle other planets, we might thoughtlessly bring small invertebrates like insects along either as a food source or as part of the ecosystem. We have an obligation to consider their wellbeing in these future scenarios as well, and avoid bringing animals into existence only to suffer.
Furthermore, if we ever develop artificial intelligences that are conscious, many of the same antispeciesist principles would apply. Consciousness is what matters, not species, size, or substrate. As artificial intelligence and biotechnology advance, we may create entirely new kinds of sentient entities. We have an obligation to consider the risks and experiences of these potential future minds.
The New York Declaration emphasizes that absolute certainty about consciousness is not required to give moral consideration to animals. There are strong reasons to think many invertebrates are conscious, and a realistic possibility of sentience creates an obligation to avoid doing things that might harm them. The declaration’s recognition of possible invertebrate sentience creates an urgent need for more safe studies to understand what might harm or help them. This research is critical to informing evidence-based policies to protect their welfare.
While the declaration is an important milestone, the case for invertebrate sentience is not new. Philosophers and activists have long argued for the moral consideration of invertebrates based on their capacity for subjective experience, and the 2012 Cambridge Declaration on Consciousness recognized the likelihood of consciousness in many nonhuman animals. The Cambridge Declaration, which was written as the summary of the Francis Crick Memorial Conference, makes a stronger statement about octopus sentience, and further includes this in a footnote: “While it is indisputable that all vertebrates, including fish and reptiles do possess the neurological substrates of consciousness, and that there is further very strong evidence to support that invertebrates, including but not limited to decapod crustaceans, cephalopod mollusks, and insects, also do, only octopuses were explicitly named because there was a scientific presentation on them at the conference.”
What’s new in the New York Declaration is the growing mainstream recognition of this possibility and its ethical implications.
What can you do? Support non-harmful research into invertebrate sentience. Avoid products that come from invertebrate farming. Advocate for policies that take invertebrate welfare into account. And spread the word about the New York Declaration on Animal Consciousness and the compelling evidence of consciousness in a wide range of animals.