Skip to main content

Does it matter if an octopus has consciousness?

Updated Thursday, 23rd July 2015
Are cephalopods self-aware? More to the point, does it even matter? The Cephalover Mike Lisieski explains just why it's important.

This page was published over 7 years ago. Please be aware that due to the passage of time, the information provided on this page may be out of date or otherwise inaccurate, and any views or opinions expressed may no longer be relevant. Some technical elements such as audio-visual and interactive media may no longer work. For more detail, see how we deal with older content.

Consciousness is a difficult term to define, but (working from the Stanford Encyclopedia of Philosophy page on the subject) it seems to be best captured by the criterion of awareness. A conscious creature is one who is aware of the world, who has some subjective state which allows them to experience things. More strictly, we might say that a conscious creature must be aware of itself – it must have some notion that it exists, and that it is separate from the rest of the world. Obviously, the ability to have complex internal representations of things is generally considered a prerequisite to this sort of consciousness. This is sometimes called “cognitive ability” (perhaps more properly, the abilities to perform various tasks requiring this capacity are called “cognitive abilities”.) It does not necessarily imply consciousness, but consciousness as defined here requires that an animal to be able to form such representations of the world “before” it can be considered conscious.

Ocellated octopus Are you thinking 'what's he thinking'? An ocellated octopus

Some authors use the term “primary consciousness” and “secondary consciousness” to refer to different aspects of what others call “cognition” – that is, an animal with “primary consciousness” has awareness of sensory impressions and emotions, and an animal with “secondary consciousness” can think about its experiences.  Either of these abilities might be spoken of as being part of the workings of cognitive abilities, with or without any implication in consciousness.  The primary/secondary terminology emphasizes that consciousness probably comes in many varieties that cannot always be easily described using the binary concepts of “conscious” and “non-conscious”.  This is especially important to keep in mind when talking about animal consciousness, as it is likely than other species have consciousness that is qualitatively very different from ours, but can still be identified as the same type of phenomenon.

It’s relatively easy to determine if a human is conscious; you just ask them. The fact that we can use language makes it very easy to determine if a human is currently conscious (that is, not in a deep sleep, dead, or in a coma.) In general, though, we’re comfortable making the assertion that humans are conscious. It is much harder to make this case with non-human animals (hereafter just called “animals”.) Because animals generally cannot directly report their experience to us – or because we cannot understand their reports well enough – we have difficulty knowing from an animal’s behavior whether or not it is conscious, or how to characterize its possible consciousness. We can determine the extent of an animal’s cognitive abilities relatively routinely using a variety of tests. This approaches the problem of consciousness tangentially, and from these tests we derive most of our information about the possibility of consciousness in animals. I’ll get more into this in Part 2 of this series of posts. For now, another question is at hand:

Who cares? Why in the world should we be concerned with the mental states of animals? In particular, why do we want to know if cephalopods are conscious?

I’ll answer this question two ways: first, as a scientist, and second, as an ethicist.  There are probably other reasons to care, and I cannot cover either of the ones I have chosen exhaustively.  In any case, let’s press forward:

Scientifically, the question of animal consciousness (mostly studied these days in terms of animal cognition) is exceedingly important to neuroscience, zoology, psychology, and biology-in-general. If we accept the dogma of neuroscience, specifically that the nervous system is responsible for all of the behavioral and mental processes of an animal, then it must be that the brain of an animal is responsible for that animal’s consciousness (humans included.) If neuroscience is supposed to learn how the brain works, then it within the goals of neuroscience to understand how the functioning of the brain gives rise to consciousness. As neuroscience is not just about human nervous systems, but nervous systems in general, it is important that we know whether animals are conscious, and if so how this consciousness might differ from or be similar to our own consciousness.

Besides being a good subject for science fiction movies, “solving” consciousness in terms of neural function would also be a huge theoretical milestone for neuroscience and computer science. It might allow us to construct computers that were conscious, and could perform tasks with human-like (or even animal-like) intelligence. Because consciousness is widely thought of as one of the most complex and integrative brain functions (that is, it involves the action of a very large and very variable group of brain areas and functions,) it is likely that, by the time we reach this goal, we will have solved most of the rest of the functions of the brain as well. Thus, understanding consciousness is an important goal in neuroscience.

In zoology, ethology, and psychology, all of which attempt (at least in part) to understand behavior, the question of animal consciousness is central. If animals use conscious processes to make decisions, then it is appropriate (and indeed, necessary) that we identify these and study the animal’s behaviors on these terms. As it stands, cognitive processes are recognized throughout a wide swath of the animal kingdom, but we have yet to reliably extend our inquiry to consciousness. Thus, understanding if and how animals are conscious is important to understanding animals and their behavior in general, which is the goal of these disciplines.

Why cephalopods, though? Cephalopods are a unique group of model animals in the comparative study of the brain and behavior. Most of the anatomy (and presumably the function) of their nervous systems evolved independently from the other animals we usually grant “cognitive” or “conscious” status to (eg. birds, mammals, and possibly reptiles.) When we theorize about the relationship between neural function and cognition, we can use cephalopods as a way to test our theories about what sorts of neural circuits and/or patterns of activity correspond with different cognitive faculties and conscious states. This is only true if, in fact, cephalopods can be conscious. As far as cephalopods are generally useful in developing theories of behavior and brain function in general, they are useful in the scientific study of consciousness – that is, if they are conscious. Thus, determining whether cephalopods are or are not conscious is important to the future of the comparative study of behavior and cognition.

Finally, the question of cephalopod consciousness has implications for how humans should use animals – that is, in terms of the ethics regarding the way that humans interact with other animals. Panksepp (2005) lists 5 reasons for studying affective consciousness (while he’s interested in emotions, many of the same arguments apply to consciousness in general,) including the following: “an understanding of affect in the lives of other animals may be critical for making informed choices on how we ethically treat other creatures… By failing to study such issues, we may continue to deny animals the respect they deserve.”

If we are going to have a rational ethics that can instruct us as to what is permissible and what is not permissible to do with animals (a goal that all of us should have,) we need to know if animals experience the world, and if they do, how they experience it. The ethical stance most commonly taken when looking at the use of animals by humans, welfarism, has at its center the idea that the suffering and discomfort of animals should be considered when using animals; specifically, the suffering of any animals that people use should be minimized. The focus is on the “welfare” of the animal, which means its general well-being, comfort, and quality of life. This is different from the case for “animal rights”, which ascribes to animals rights not to be treated as a means-to-an-end that, like the rights we ascribe to people, would prevent them from being ethically used by humans at all. As (for example) researchers, farmers, and the pet industry are still using animals, and they (and by proxy, all of us who make use of their discoveries and products) depend on the continued use of animals, we mostly reject the latter argument, focusing on the welfare of animals instead of the rights of animals. It’s a somewhat subtle distinction, but it’s important. From a welfare-based perspective, which is based on preventing suffering, it is important to know how animals can suffer. It seems likely that having self-awareness can allow an animal to suffer in more and possibly deeper ways – for example, from loneliness, self-pity, shame, boredom, unfulfillment, anger, and so forth. Thus, the question of animal consciousness is important to animal welfare-based ethics. From a rights-based perspective, the consciousness of animals is not as important. The supposed right of animals not to be used by humans is intrinsic to sentient animals (that is, animals who can sense and react to their environment.) From this viewpoint, regardless of their specific capacity for cognition or conscious awareness, these animals should be protected from human use. I’ll just (for convenience, because it’s what I believe, and because it’s the dominant view, socially speaking) adopt a welfarist perspective on the ethics of the use of animals.

Common octopus A common octopus - but an uncommon intellect?

How does this apply to cephalopods? Well, humans use a lot of cephalopods. More than 4 million tonnes of cephalopods were harvested from the oceans in 2007, according to the FAO yearbook of Fishery and Aquaculture Statistics for that year. Perhaps particularly troubling, depending on the capacity of cephalopods to suffer, is the practice of eating extremely fresh cephalopods – that is, those who are still alive (or killed/incapacitated just prior to eating,) which, as a quick YouTube search will attest, is not unheard of in southern Asia and maybe elsewhere. In addition to their use as food, smaller numbers of cephalopods are kept as pets, as research animals, and in aquaria. If the study of the possibility of consciousness in cephalopods is necessary to inform our ethics regarding how we treat cephalopods (and it seems like it is, given how important consciousness appears to be to our common-sense notions of “suffering”, and even some philosophical formulations thereof) then we should get on the ball and pursue this research.  That is, if we accept the welfarist position, and we want to have a scientifically reasonable ethical viewpoint, both of which I think are relatively conservative assumptions.

I should note, before I finish this up, that the science of animal consciousness and the ethical question of animal consciousness relate to each other, but make different assumptions. Scientists are necessarily conservative about making positive assertions, and for good reason – it’s bad science to speak as if a thing (like consciousness in non-human animals) exists if there’s not some positive evidence for it. Put another way, scientific theorizing is set up to rigorously avoid false positives. On the other hand, in a system of ethics that is based on preventing suffering, it’s more important to avoid false negatives than to avoid false positives. In making an ethical decision about a certain animal (or person,) one would rather accidentally treat an agent that doesn’t need ethical considerations as if it does than to unwittingly subject that agent to undue suffering by assuming that it doesn’t have the capacity to suffer in a certain way. Thus, welfare ethics demands that we fastidiously avoid false negatives in the case of consciousness and other psychological phenomena that might determine an animal’s capacity to suffer, even at the expense of occasional false positives.  Essentially, given no other information than our impression that animals might have consciousness, a scientist should assume that they don’t, and an ethicist should assume that they do.  The best solution to me seems to be to entertain both ideas, and apply them to different problems as the specific problems demand it.

I suspect that this mention of the ethics of using cephalopods will garner more attention than the discussion of the scientific value of the study of consciousness in cephalopods, if only because animal ethics is more politicized than the comparative psychology, and is perceived as somewhat easier to talk and theorize about without much technical background.  I don’t want it to seem as if I’m making an argument for or against any use of cephalopods at this point – although I think this is an important issue, I’m not trying to deal with it here.  I’ve tried to keep this post free of any ulterior agenda, and I think I’ve largely succeeded.

This article was originally published at the Cephalove blog under a CC-BY-NC-SA licence

If you're really interested, why not explore the courses offered by The Open University in psychology and philosophy? You might really like our BA in Philosophy and Pyschological Studies.


Become an OU student


Ratings & Comments

Share this free course

Copyright information

Skip Rate and Review

For further information, take a look at our frequently asked questions which may give you the support you need.

Have a question?