Who would expect to see complex social behaviour suggestive of cognition in a manta ray? These large fish have an ancient lineage. They are not even proper bony fish but have a rubbery cartilaginous skeleton and are closer to sharks. But they are unusual in that they have evolved large and sophisticated brains, even for their size.
When one, known to divers as Freckles, got some fishing hooks caught under one eye she turned to them for help, repeatedly showing them the problem until one of them could get the hooks out. Then she circled him, apparently in a show of gratitude, before swimming off.
Cognition is not just about receiving and processing sense imporessions from your environment, but about understanding what those impressions are telling you and modifying your behaviour accordingly. Freckles' behaviour can only be explained if she has some cognitive model of the world around her and some ability to think her way round problems. She unmistakably knew what she was doing.
Many fishermen claim that fish are too simple and primitive to feel pain, they are not sentient beings. But of all the weird and random things that can happen to a manta ray in the untamed oceans, why should Freckles single out the fish hooks for medical attention if they did not hurt like blazes?
The manta ray clearly feels pain, or at least some cognitive equivalent. But does that necessarily mean that it is consciously aware, that it subjectively experiences something like creativity and pain? Might its abilities simply be hardwired by evolution?
Behaviourism was a theory, very fashionable at one time, which held that scientifically speaking even the human mind was hardwired, or at least programmed, in this way. The harder behaviourists regarded that as carte blanche to treat inner experience as fundamentally nonexistent, an extreme which even its arch protagonist, B.F. Skinner, confined only within the laboratory. Nowadays we are sophisticated enough to have demonstrated the crudity and inadequacy of behaviourism in explaining the human mind. Yet for simpler creatures with no significant brain at all, its tenets still serve us well and have sunk in so deep as to no longer be thought a distinct "ism" from the rest of animal biology. Where do we draw the line?
Our inner life is deeply connected to the information our cognitive bran structures process. Indeed, there is a growing view that "consciousness is what information feels like to itself when it reaches a certain level of complexity". Cognitive behaviours are defined precisely by the existence of such information processing going on in the background. Yet there are signs that even in the human brain, much of this processing goes on at an unconscious level, with our consciousness being informed of the outcome anything up to a second or so after the event.
One must assume that much of the manta ray's cognitive processing is similarly unconscious. But is there a consciousness in there, an experiential awareness of the outcome? The human brain has identifiable "consciousness circuitry" forming large parts of its outer cortex. We may assume that any creature whose brain exhibits similar structures must also be supporting similar subjective experiences. The manta ray does not have such highly evolved structures, but that does not necessarily mean that it is not sentient. We need to look deeper into the way the brain abstracts and supports cognitive awareness.
The manta ray is merely the latest in a long list of creatures with brains large and complex enough to demonstrate advanced cognitive and mental abilities. The Cambridge Declaration on Consciousness acknowledges the octopus among our cognitive cousins when it states:
“The absence of a neocortex does not appear to preclude an organism from experiencing affective states. Convergent evidence indicates that non-human animals have the neuroanatomical, neurochemical, and neurophysiological substrates of conscious states along with the capacity to exhibit intentional behaviors. Consequently, the weight of evidence indicates that humans are not unique in possessing the neurological substrates that generate consciousness. Non-human animals, including all mammals and birds, and many other creatures, including octopuses, also possess these neurological substrates.”
Birds shown to have exhibited suitably high-level cognition include several species each of the parrot and corvid (crow) families. Besides the octopus, I am not sure whether its relatives the squid and nautilus share those same neurological substrates. I should love to know too whether Freckles has the equivalent. But whether she does or not, we now know of at least four separate evolutionary lineages to sentience, Wow! That strongly suggests that wherever animal-like life arises, in due course sentient beings will apear.
And where do we draw the line? If a species shows a mere residual cognition, is there necessarily some sentient consciousness accompanying it? Even the bee, one of the more intelligent insects, is beginning to raise such questions. It has more of a nerve complex than a real brain, but its behaviour is proving more sophisticated than hitherto suspected and is increasingly being described in the language of cognition. What information might lurk within those patterns of nervous activity? Perhaps one day we shall find out.
We are beginning to learn just how full of inner experience the animal kingdom must really be, the story of Freckles is a real wake-up call. Moralists, neurologists, psychologists and computer scientists can no longer assume that all animals are "dumb". Society can no longer stumble on in the belief that abuse of individual animals is as acceptable as the abuse of individual plants.
It is harder to say "stop fishing" or "go vegetarian", for pain, mayhem and death are inevitable accompaniments to the sentient circle of life. Few creatures outside of human captivity have ever died of old age. But let us at least be honest about it and as humane as possible.
Updated 13 July 2019