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In recent decades, experiments have begun to catch up with what people who work closely with animals have always known 鈥� that animals have an inner life, and consciousness isn鈥檛 uniquely human.
Consciousness is a concept that is fiendishly difficult to define. There have been many attempts: is it awareness, or awareness of that awareness, or self-awareness instead? But a useful working definition might be that it is any kind of subjective experience, ranging from how we perceive the external world to our inner thoughts and emotions. Because you can never be inside another living being鈥檚 head, questions of consciousness are both hard to answer and open to bias.
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Historically, scientists referred to 鈥渓evels of consciousness鈥�, with humans at the top. But as David Robson has written for 快猫短视频, a 2020 paper argued that, instead of a hierarchy of consciousness, we should instead think about five different elements of conscious experience. Put simply, these elements are: how well an animal perceives each of its senses; how well an animal assesses the difference between bad and good; how much an animal pulls together sensory information into a single experience; the degree to which an animal鈥檚 past shapes their present behaviour and future plans; and the feeling of selfhood.
Which animals have consciousness?
Animals differ in their scores for each of these facets of consciousness. Members of the crow family, for example, can be skilled at learning from past experiences. Both octopuses and bees appear to enjoy playing, suggesting they can experience pleasure, linked to the ability to feel the difference between good and bad. The number of animals that pass the famous mirror test 鈥� showing that they understand that the animal in the mirror is them, and thus they have a sense of selfhood 鈥� is ever-growing and includes some fish but not dogs.
Findings like this prompted a group of scientists in April to write The New York Declaration on Animal Consciousness, which now has over 300 signatories. It states that there is 鈥渟trong scientific support for attributions of conscious experience鈥� in mammals and birds and 鈥渁t least a realistic possibility of conscious experience鈥� in fish, amphibians, reptiles and some invertebrates, including molluscs, crustaceans and insects. The latter part of this is the most attention-grabbing 鈥� could insects really be conscious? 鈥� but it鈥檚 notable that to suggest mammals and birds experience a degree of conscious experience doesn鈥檛 feel all that controversial anymore.
This wasn鈥檛 always the case 鈥� as recently as 2012, scientists felt it was necessary to issue a Cambridge Declaration on Consciousness, which stated that 鈥渢he weight of evidence indicates that humans are not unique in possessing the neurological substrates that generate consciousness鈥�. This declaration noted that all mammals and birds, and some other animals like octopuses, have the neural machinery needed to generate conscious states and intentional behaviours.
Humans aren鈥檛 unique
That animals have some form of inner life must surely be self-evident to many people who live or work with them, just as I would guess that most carers of newborn babies don鈥檛 see these infants as senseless automata. The experiences of people with intimate knowledge of either have, historically, been easy to dismiss as subjective and biased, with emotional connection getting in the way of rationality. Our consciousness leads us to over-empathise with others we cannot truly know are like us, the argument goes.
But, as the biologist Marc Bekoff wrote in 快猫短视频 at the time of the Cambridge declaration, Charles Darwin鈥檚 ideas about evolutionary continuity between species led him to conclude that if we, humans, have something, then they, other animals, are likely to have it too. I personally feel (thanks to my consciousness, I suppose) that attempts to divorce emotion, feeling and experience from how we see animals can be just as unscientific. For too long, we assumed that humans are unique and animals don鈥檛 feel pain or emotions the way that we do, a convenient but cruel null hypothesis, when we could have started from the position that perhaps they do instead.
