When even a fish is self-aware, being a human doesn’t seem so special
Is a fish self-aware? Is it, in other words, conscious of its existence as something separate from its environment? A new study shows that at least some fish can pass the standard cognition test – that is, they can recognise themselves.
When a reef fish known as a cleaner wrasse ( labroides dimidiatus) is placed before a mirror, it notices if it has had a coloured mark placed on it and seeks to scrub the spot away.
Human beings typically reach that level of cognition at around 18 months. The change is quite sudden, and marks an important moment in our cerebral development.
A toddler becomes aware, from one day to the next, that the image in the glass is not another toddler. At roughly the same time, that toddler starts making self-conscious decisions.
Awareness of yourself as a discrete entity is thus traditionally seen as the basis of free will. When Adam and Eve ate fruit from the tree of knowledge of good and evil, “the eyes of them both were opened, and they knew that they were naked”. Self-awareness, in other words, makes us capable of moral choices.
What, then, are the implications if mirror self-recognition is not limited to human beings, nor even to apes and higher mammals, but is shared even by darting blue fishes? One possibility offered by the authors of the report is that the mirror test is an inadequate way to measure cognition.
A second is that levels of sentience in the rest of the animal kingdom are vastly higher than we used to think – an uncomfortable finding, given the way we use other species.
But perhaps we are approaching this the wrong way around. Perhaps, if fishes have self-awareness, we are not nearly as special as we think. The story of the past 500 years is the story of the gradual dethronement, at least in our scientific understanding, of the human race.
We have had to come to terms with the fact that Earth is not the centre of the universe, that we are descended, not just from apes but from viruses, and that our brains are made up of the same ingredients as inert matter. What we think of as the “us”, the special bit that makes decisions, is a series of electrical pulses – pulses that also flow through fishes. The concept of the self is an illusion put on by the nervous system.
This is, on the surface, a terrifying finding, which is why so many of us struggle against it. If we are nothing more than the sum of a series of molecules, then our apparently conscious choices must have purely material causes. It is not only the soul that is redundant, but any notion of responsibility, virtue or blame. “For dust thou art, and unto dust shalt thou return.”
We can’t even console ourselves with the idea that self-awareness is a consequence of complexity. Planes fly themselves without self-awareness. Computers beat the best human chess-players. It increasingly appears that consciousness is a purposeless side-effect of the firing of our neural networks, that all the woes and joys that fill our lives are accidental by-products.
To which the most sensible response is surely: “So what?” We can’t know for sure whether the cleaner wrasse has a conscious mind. Then again, we can’t know for sure whether any other human being has a conscious mind. It is known in philosophy as the problem of solipsism. Except it isn’t a problem at all. We infer from our subjective experience and from other people’s outward behaviour that they probably have minds like ours and, if we’re wrong, so what? The possibility that fishes are self-aware changes everything; yet, at the same time, it changes nothing. FOLLOW Daniel Hannan on Twitter @DanielJHannan; at telegraph.co.uk/opinion