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Octopuses Gain Consciousness (According to Scientists’ Declaration)

The views expressed are those of the author and are not necessarily those of Scientific American.

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octopus consciousness declaration

Octopus uses empty shells to hide; image courtesy of Wikimedia Commons/Nick Hobgood

Elephants cooperate to solve problems. Chimpanzees teach youngsters to make tools. Even octopuses seem to be able to plan. So should we humans really be surprised that “consciousness” probably does not only exist in us?

This privileged state of subjective awareness in fact goes well beyond Homo sapiens, according to the new Cambridge Declaration on Consciousness (pdf), which was signed last month by a group of cognitive neuroscientists, computational neuroscientists, neuroanatomists, neuropharmacologists, neurophysiologists who attended the Francis Crick Memorial Conference on Consciousness in Human and non-Human Animals at Cambridge University in the U.K.

“The weight of evidence indicates that humans are not unique in possessing the neurological substrates that generate consciousness,” the scientists wrote. “Non-human animals, including all mammals and birds, and many other creatures, including octopuses, also possess these neurological substrates.”

The octopus is the only invertebrate to get a shout-out at all. And plenty of research has been accumulated to back up this assertion. A 2009 study showed that some octopuses collect coconut shells to use as portable shelters—an example of tool use, according to the researchers. Other research has documented sophisticated spatial navigation and memory. Anecdotal reports from researchers, such as Jennifer Mather, describe watching octopuses in the wild make errands to collect just the right number of rocks to narrow the opening to a desired den. And laboratory experiments show a distinct change in behavior when octopuses are kept in tanks that do not have enough enrichment objects to keep them stimulated.

What was keeping scientists from accepting the existence of consciousness outside of our own family tree? Simple brain anatomy. Older models of brain activity lodged complex, conscious experiences—like musing about a piece of music or reminiscing about a piece of cake—in our highly evolved cortex. But, as the authors of the new declaration noted, many nerve networks involved in “attentiveness, sleep and decision making appear to have arisen in evolution as early as invertebrate radiation, being evident in insects and cephalopod mollusks (e.g. octopus).”

Even emotions (or, according to the declaration, their “neural substrates”) are not dependent on an animal having particular brain structures, such as our cortex, after all. In fact, many other neural regions are activated when we emote and “are also critically important for generating emotional behaviors in animals,” the scientists noted.

That does not necessarily mean that you could have a distraught octopus or an elated cuttlefish on your hands. But this new, formalized conception of consciousness does suggest that the octopus has used its own, more foreign-looking brain to develop some sense of subjective experience.

“Exactly how organized brain matter gives rise to images and sounds, lust and hate, memories, dreams and plans, remains unclear,” Christof Koch, chief science officer at the Allen Institute of Brain Science, and co-presenter of the new declaration, recently wrote in the Huffington Post. And although brain structures, such as the cerebral cortex, in mammals seem to be highly conserved evolutionarily, Koch noted, other organisms, such as birds and cephalopods force us to reexamine other neural components of consciousness. “The challenge that remains is to understand how the whispering of nerve cells, interconnected by thousands of gossamer threads (their axons), give rise to any one conscious sensation,” he wrote.

And so, with the new declaration (and with apologies to David Foster Wallace), science has considered the octopus. And found it conscious. …Now we just need to figure out what, exactly, the octopus experience is.

Illustration courtesy of Ivan Phillipsen

Katherine Harmon Courage About the Author: Katherine Harmon Courage is a freelance writer and contributing editor for Scientific American. Her book Octopus! The Most Mysterious Creature In the Sea is out now from Penguin/Current. Follow on Twitter @KHCourage.

The views expressed are those of the author and are not necessarily those of Scientific American.

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  1. 1. timbo555 8:14 pm 08/21/2012

    How about self-regard? Can the scientists, or better the octopi itself (a more appropriate plural, yes?) demonstrate a consciousness that suggests: “I think therefore I am”? Or have they determined merely that they are clever at getting a bit of crab-meat out of a sealed baby-food jar?

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  2. 2. Na g n o s t ic 8:34 pm 08/21/2012

    Even the most primitive humans from antiquity have assigned “consciousness” to various animals and plants, and often minerals as well.

    It seems to me it’s been western scientists who’ve often denied the existence of consciousness regarding non human beings as well as human infants.

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  3. 3. Na g n o s t ic 8:39 pm 08/21/2012

    I’m sure the only reason for the new-found recognition of the obvious for so many for so long is to justify certain environmental regulations being concieved by the political funders of these newly aware scientists.

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  4. 4. Trafalgar 9:35 pm 08/21/2012

    Gain? I think perhaps you should be more careful with your word choice.

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  5. 5. Spin-oza 9:42 pm 08/21/2012

    WOnderful! About time the neurocognitive experts issued a consensus statement of the widespread abilites among the animal kingdom… from which humans evolved and are fully embedded. It should be of absolutely no suprise to any “thinking” person, free of religious bias of some “special status” for humankind, apart from Nature… when all evidence and observation should make it beyond question we are a part of Nature.
    Yes primates… hominids… have evolved along diffent a different branch were the neocortex was highly conserved as Professor Koch phrased it. But all our abilities are different only by degree. Every time some dimwitted religious person seeks to undermine the edifice of evolution… and claims “special creation” for humans… and all our “unique abilities”… it only shows how indoctrinated and delusional they have become.
    It’s a sad state of affairs that the substance of this article is “news”… but even sadder that the vast majority of Americans will reject it out of hand.
    BTW… the eye of a cephalapod is more “intelligently designed” than that of a “modern” human… LOL!

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  6. 6. blindboy 5:59 am 08/22/2012

    Someone should explain this to the philosophers who still seem to imagine that human consciousness is fundamentally different from that of other animals. Human consciousness obviously does have significant differences but it lies along a continuum rather than being categorically different.

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  7. 7. ACTORwriter 9:01 am 08/22/2012

    This whole concept of “consciousness” is SO nebulous as to verge on nonsense. Do we extrapolate the idea to also indicate “SOUL”? And isn’t THAT subject to dubious controversy as well?

    Decision-making, enjoyments, anger, planning, predictions, eagerness, recognitions, memory, and on and on — how many attributes are necessary before we accord an animal or bird the lofty facility which we have smugly thought was province of humans alone, i.e. “consciousness”?

    For four years now I have had a male American Robin friend (migrating every winter) who has deigned to fly to my hand for food, or sit on my lap to enjoy an extended meal, or fly next to my shoulder to say, “Hey, what about me?” Bear in mind he recognizes me IMMEDIATELY upon his return each March, though he won’t dare fly to anyone else. He can distinguish me from other humans; I don’t do that well distinguishing one robin from another.

    No, “consciousness” is simply being AWARE. That’s the long and short of it. The accomplishment belongs to most animals and birds. It comes from the need to survive.

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  8. 8. Achille Talon 10:16 am 08/22/2012

    So, Paul the octopus, who predicted right the results of the last Mondial of soccer, was finally totally conscious about what he was doing. :-)

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  9. 9. Torbjörn Larsson, OM 12:32 pm 08/22/2012

    this new, formalized conception of consciousness

    My main problem with “consciousness” research is precisely that it isn’t formalized. The declaration abstain from well defining what “consciousness” is and/or what constrains it.

    Stripping away the dross it seems however to be equivalent to being awake, or more precisely to display ““attentiveness, sleep and decision making” behavior. This goes back to nematodes having sleep analogs (and I’ll bet analogs to emotional equivalent “tiring” as well).

    In other words, how is research on “consciousness” different than research on mind (brain & coupled body) function?

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  10. 10. Cognosium 4:12 pm 08/22/2012

    Within the context of modern science there is nothing at all surprising in such assertions of consciousness in other creatures.
    We now have conceptual tools that provide a full empirical understanding of the general nature of consciousness.

    Firstly, and most importantly, from our understanding of biological evolution by natural selection it becomes quite clear that the provision of a navigational feature that involves some degree of self awareness is required for an organism to interact optimally with its environment.

    It is a measure of its fitness for the prevailing environment and subject to selection pressure accordingly.

    There is, of course, a great gulf between the level of consciousness exhibited by our species in comparison to the octopus or any other. Simply because the level of interaction with the environment required by our particular ecological niche is incomparably higher. As evidenced by the billions of artifacts and systems that have resulted from human activities,

    Secondly, we can be sure that consciousness has a purely chemical basis by virtue of the fact that it can be “turned off” chemically by anesthetics. What’s more, the state (and perception) of consciousness can be modified at sub-anesthetic levels by such substances as diethyl ether, and nitrous oxide. Not to mention the wide variety of altered states of consciousness induced, again chemically, by substances such as alcohol, cannabis, amphetamines, cocaine, LSD and so forth.

    Thirdly, from computer science, we now have a good understanding of how information processing systems work. While, of course, neural mechanisms are very different from the digital electronic circuitry of our computers there are sound functional comparisons to be made and to help our understanding at a general level.

    We must always bear in mind that, most of the activity of our central nervous system performs its multitudinous complex tasks without any awareness on our part. The consciousness is merely a tiny window on the world of which we are part. Essentially just a navigational facility. Albeit a rather nifty and important one.

    That may, of course, offend anthropocentric conceits.

    If you are game to bite the bullet and have them further offended then check out my books, which are available as free downloads in e-book formats from the “Unusual Perspectives” website.

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  11. 11. SpottedMarley 4:28 pm 08/22/2012

    I’m somewhat insulted by the insinuation in your first paragraph that, as humanz, “we” are somehow surprised by something that, in my estimation, should be completely obvious to everyone. it is to me, anyway. All living things possess consciousness. In fact, all matter.. for that matter.. is, if not conscious on some level, the direct result of consciousness. I don’t share your naivety with regards to consciousness. I think what you are actually making note of is octopi “intelligence” or maybe even their IQ .. but not their consciousness. Read some better books.

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  12. 12. bucketofsquid 5:36 pm 08/22/2012

    I’ve always found the idea that only humans are conscious to be remarkably arrogant and self serving. Glad to know that I’m right to feel that way.

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  13. 13. American Muse 9:51 pm 08/22/2012

    Hinduism suggests all life has consciousness – to a greater or lesser extent. That goes further than the fatuous “Cambridge Declaration.”

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  14. 14. Bob Grumman 11:58 am 08/24/2012

    What does an ability to be subjectively aware of what surrounds us have to do with the ability to plan? The scientists investigating this seem not to be able to grasp that consciousness is unlike all matter/energy in that it is an inside. I don’t see how we can ever determine what it is. The fact that a blow to the head may seem to turn it off is irrelevant–because we can’t know whether that really turns it off or just prevent its being able to access data. Or make memories of it if it can for us so we could know that it was on. To give just one question that seems to me to make the quest to discover consciousness scientifically absurd.

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  15. 15. Bob Grumman 12:39 pm 08/24/2012

    I should add that I see no reason to believe stones don’t have conscousness.

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  16. 16. drhowardhail 3:08 pm 08/28/2012

    This is pure bs because some animal rights leaning people say so doesn’t make it so. Mark Hauser was fired from Harvard for making false reports and statements and he is the man who started this field and most of these people are his graduate students. Katherine Harmon is an animal rights proponent and is biased in this direction. I expect better of Scientific American but any journal who hires someone to write who has such an obvious prejudice loses the name of science and objectivity as this theory is still not proven. There are only a handful of people who wrote this document and proclaimed this fiction and the rest of the world does not agree. Genetics is far more complicated than these men know and frankly I am appalled that this magazine has allowed such dribble to be published as fact. The leader of this movement was found to provide false evidence in his research. The Members of this

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  17. 17. osbornej 1:14 pm 08/29/2012

    How do I download the declaration? It comes up with a title and three bullet points but no contents. I have tried to download at other websites and gotten the same blank document.

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  18. 18. osbornej 1:19 pm 08/29/2012

    Finally got to read it. Turns out the text was white on white (bizarre- why would they publish it that way?). pasted into Word and there it was.

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  19. 19. marclevesque 6:41 pm 08/29/2012


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  20. 20. Antti Kivivalli 2:16 am 09/1/2012

    What? Those two dogs next to me are not mechanical toys?!?!

    Yes, some people seem to have a need for such a declaration, so I think it is a good thing, possibly a giant leap for those prominent humans.

    In my world view they are still missing some crucial parts. First of all the mind is a feature or substance that uses the biological structure (with or without neurons or brain, even in unicellular organisms) and not that mind something that is created only as a function of a complex neurological structure.

    My muscle cells (besides having a mind of their own…) can kind of create physical movement (from chemical and physical energy) but physical movement exists as a feature of the universe even for the inanimate objects (and don’t twist me into saying that matter doesn’t have a mind, sure it does, but in a dormant state :-) ).

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  21. 21. Pazuzu 2:48 pm 09/1/2012

    This is very interesting! I’m always happy to see scientific endeavors that chip away at the anthropomorphic conceit that we’re somehow special. I recall in the dim recesses of my memory reading a claim somewhere that octopuses have been shown to have personality; I would appreciate any help in tracking this down.

    Finally, why does the author say “apologies to David Foster Wallace”? I clicked on that link and got an article in Gourmet magazine that does not even contain the word “octopus.”

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  22. 22. iyashable 12:48 pm 09/7/2012

    you get paid to write this?

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  23. 23. serge.patlavskiy 7:40 am 11/15/2013

    The Law of Conservation of Consciousness:

    1) one complex self-organizing system (either a natural living organism or an artificial structure) possesses only one exemplar of consciousness;
    2) all such systems possess exemplars of consciousness that are equal in terms of their natural mechanisms, so their potentialities;
    3) the total number of all the exemplars of consciousness in Reality is limited and conserves
    ( Section 2.4).

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  24. 24. Shamira 12:47 am 12/8/2013

    @timbo555 – No, ‘octopuses’ or ‘octopodes’ is the correct plural of octopus, not ‘octopi’. If you’re going to make condescending corrections, you should at least make sure that you’re right before commenting, otherwise you just look a bit silly.

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  25. 25. ThinkingScientist 10:56 am 10/15/2014

    “The challenge that remains is to understand how the whispering of nerve cells, interconnected by thousands of gossamer threads (their axons), give rise to any one conscious sensation,”
    The human mind is more than just neuronal connections. These scientists are never going to find how consciousness works because they have already assumed it to be a product of only neurons. There is more and more emerging proof from quantum mechanics that the mind produces matter, not the other way around. However, these scientists and the writer are mere materialistic atheistic evolutionists and their only attempt is to prove that we ‘evolved’ from random unguided processes and mistakes, without the aid of an intelligence, when all evidence suggests otherwise.

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