Grossman: A Different Flavor – Just How Smart Are Octopuses?


28 November 2013

Octopuses have a rather creepy reputation.   Let’s just say that, what the creeping spider is to dry land, the eight-tentacled octopus is to the sea – a “monster” of the deep.  These creatures have thousands of suckers on their eight “arms,” squirt dark ink, change color, and can squeeze their, sometimes, large bodies through amazingly small holes.  Also, they can move when they want to move having the ability to propel themselves by producing a jet of water in the same way jet engines propel aircraft through the air.

The octopus is a celebrated predator.   Well equipped for the hunt, the octopus has a parrot-like beak, a tongue covered with teeth, and poisonous venom.  Superficially, there’s nothing about the octopus that would put anyone in a warm or cuddly mood.  But like some seemingly forbidding people you may have met, it seems that the better you get to know the octopus, the more favorable (and friendlier) your opinion becomes.

Scientists have recently discovered that octopuses might be intelligent – much more intelligent than anyone had ever suspected.  However, this is one of those discoveries that seems like “yesterday’s news.”  When you read accounts of octopus behavior, the fact that octopuses are intelligent is like the proverbial “elephant in the living room.”  How could anyone have missed it?

Consider Otto, an octopus resident at the Sea Star Aquarium in Coburg, Germany.  Otto shares a large tank with hermit crabs, which he probably traumatizes on a regular basis with his ideas of fun.  Among other activities, Otto likes to juggle the helpless crabs, throwing them, not in the air, but up above him into the tank’s water.  Being repeatedly tossed by a two-handed juggler would be bad enough, but you can only cringe at the thought of the experience with eight-hands.

Otto’s behavior isn’t particularly unusual.  In an experiment, Roland Anderson, gave octopuses small pill bottles, each of a different color, to evaluate the creatures’ color preferences. Most of the octopuses lost interest when they realized the bottles weren’t food, but one blew a “modulated” jet of water at the bottle sending it swirling to the other end of the tank and back to the sender – repeating this action 20 times.  Anderson compared the action to the human version of bouncing a ball.  Another octopus, in the same group, was caught using its water jet to propel its bottle back and forth over the surface of the water.

What’s so significant about all this?  It’s play.  Anderson’s observations appeared in the Journal of Comparative Psychology. “Only intelligent animals play—animals like crows and chimps, dogs and humans.”

Although, sometimes, Otto seems more like a candidate for the staring role in an upcoming documentary, “When Good Octopuses Go Bad,” he demonstrates a mastery of tool-use when he throws stones into front glass of his tank (damaging the aquarium glass several times).  In spite of Otto’s disruptions and vandalism, his behaviors are clearly intelligent.

Octopuses gather building materials as part of what is, sometimes, called their fortress behaviors.  These creatures tend to settle in a location and fortify the perimeter with a variety of building materials.  And, in the act of collecting these building materials, the octopus displays one of its most amazing characteristics.  Most animals either use or discard an item that is of no immediate use.  In other words, most animals have no ability to delay gratification and, therefore, do not appreciate the need to find, hold, or transport items that may be of value at a later time.

The Veined Octopus, however, retrieves discarded coconut shells, transports them over a distance, and reassembles them to build a shelter.  This behavior demonstrates selection of a tool and, then, holding the tool exclusively for a later use.

You might think of this behavior as resembling grocery shopping.  When you go to the store, you don’t eat the food you want straight off the shelves and, then, leave without taking any food with you.  Rather, you gather food, groceries, and take it home for future use.

And, it so happens that octopuses often gather food in a way not so different from human grocery shopping.  As it hunts, this creature picks up all the food it can carry and transports the load home.  It will eat the food, at its leisure, later.  With eight arms, an octopus can carry a lot of food, but sometimes its eyes are bigger than its eight-armed carrying capacity.  If it finds its load is too heavy for the trip home, it simply makes an unscheduled stop, eats its “groceries” down to a portable volume and, then, continues home with what’s left.

But octopuses demonstrate other intelligent behaviors.  They are also problem solvers. Wilson Menashi designed a puzzle consisting of three plexiglas cubes each with a different type of latch.  When food was placed in the first box and given to an octopus, the creature quickly managed to figure out how to open the box.  Then, the first box was locked in the second box.  Again, the octopus quickly learned to open both boxes to get to the food.  The same swift mastery followed the addition of a third box.  Sadly, when the octopus’s food of choice, crab, is unavailable, some octopuses turn their problem solving abilities to crime.  That is, octopuses sometimes rob lobster traps, which they learn to open with relative ease.

So, you would never want to snooze on the beach with a crab in your pocket.  That crab would be awfully tempting to passing octopus.  Oh, . . . you thought you’d be safe because you weren’t in the water?  Surprise!  Many octopuses seem never to have learned that they are sea-dwelling creatures.  They tend to jump onto land at the least provocation.

An octopus was recently, not just caught on land, but also caught on video grabbing a snack on the beach — completely out of the water.  These creatures like to eat crabs so much that they have been known to climb on board fishing boats, jump into containers of dead crabs, and pig-out. As a matter of fact, aquariums sometimes have difficulty keeping these creatures in the water.

Otto, for example, thought the overhead light in the Sea Star Aquarium was too bright, and his irritation was only relieved by occasional mysterious power failures.  While the failures gave Otto a break from the bright light, the cessation in the filtration systems in the aquarium’s tanks was a positive danger.  When the power outages became more frequent, the staff organized a stake-out of the area, day and night, to find the cause.  On the third night, Otto climbed out of his tank and directed his jet-stream of water at the irritating light above his tank and continued to do so until the system shorted and the power failed.  The light has been re-installed in a location beyond the range of Otto’s water-jet.

Octopuses frequently put their water-jets to other creative uses.  Octopus Truman of the New England Aquarium developed an aversion to one volunteer and used his water-jet to soak her with salt water at every opportunity.  She eventually quit her volunteer position, but returned for a visit a few months later.  As she entered the lab she was drenched in saltwater by Truman’s jet.  Apparently, Truman remembered her.  He had not sprayed anyone with water since her departure months earlier.

Researching her senior thesis in the octopus lab at Middlebury College, Alexa Warburton often struggled to remove reluctant octopuses from their tanks. The creatures had mastered all the skills I employed on a particular day when I tried to avoid attending the first grade.  The octopuses would hide in the corners of their tanks or hold on to objects and not let go. In fact, octopuses in captivity escape their tanks with great frequency.  When the creatures were removed from their tank, a few used the net as a kind of trampoline bouncing off the net and onto the floor.  Then, they’d make a run for it.  And they’d “run,” Warburton emphasized, “You’d chase them under the tank, back and forth, like you were chasing a cat.”  “It’s so weird!”

When you understand how octopuses behave, it’s tough to understand how their intelligence could have been overlooked for so long.  Perhaps, in the past, science has been too physiologically minded.

For example, several species of birds have recently demonstrated remarkably high levels of intelligence and even self-awareness.  The last common ancestor of human beings and birds roamed the earth about 300 million years ago.  During the last 300 million years, the brains of birds and mammals developed along separate lines.  Scientists were sure that the mammalian brain’s neocortex made certain species, including human beings, self-aware (i.e., conscious).  Problem.  Several species of birds pass all the self-awareness tests with flying colors, but their brains are the size of walnuts and they have no neocortex.

Then, there’s the octopus.  Octopuses are mollusks, invertebrates, closely related to the clam.  Clams don’t even have brains.  The last common ancestor of human beings and octopuses lived between 500 and 700 million years ago.  From that point on, human and octopus brains developed along separate lines in quite different environments.  The octopus brain is about the size of a walnut with only about 130 million neurons compared to the 100 billion of the typical human brain.  However, you don’t need these numbers to see some staggering differences.  For example, humans have one brain, but “three-fifths of the octopus’s neurons” are in the octopus’s arms and not their “head.”  It seems that intelligence doesn’t have as much to do with brain size as was once supposed.

Perhaps, the intelligence of octopuses was overlooked because of their lack of social behavior.  These creatures are one of the most unsocial animals you could imagine.  Their contacts with their fellow creatures result in either one octopus eating the other or mating.  There are no other social encounters with their peers.  Period.  In the first instance, predation, one octopus dies when it’s eaten.  In the second, mating, both octopuses die because disorientation and death follow swiftly.

Much of our appraisal of the intelligence of any animal is based on observation of social interaction.  But, in the case of the unsocial octopus, you have to observe its relationship with its inanimate, physical environment to appreciate its intelligent behavior and evaluate the scope of its intelligence.  Strangely, the captive octopuses that are the subject of study in laboratories seem to enjoy a richer relationship with their human captors, than any of their own species.  But, perhaps, even this relationship is the simple result of the dependence of the captive octopuses on their human captors for survival (food).

Maybe it’s the plain strangeness of both the octopus and its intelligence that so long delayed the “discovery” of the creature’s intelligent behavior.  Philosopher Peter Godfrey-Smith compared encountering the octopus with “meeting an intelligent alien.”  And, indeed, everything seems so “out-of-whack” when you learn about the octopus.  For example, octopus communication is limited to changes of color.  An octopus uses color changes to camouflage itself, express emotions, and warn off (frighten) predators.  But the octopus’s use of a wide range of color displays becomes confusing when you discover that these creatures are colorblind.  But, then, you discover that octopus “skin contains gene sequences usually expressed only in the light-sensing retina of the eye.”  So, octopuses may be able to see color with their skin.

In the end, what can we say about the octopus as an intelligent being?  It is an alien.  An immensely ancient alien that evolved on the ocean floor — the oldest and most enduring environment provided by the hydrosphere we call Earth.  However, “alien” is a relative term.  Compared to the octopus, we are the newcomers.  We are one of a group of strange, and relatively new, life forms that live on those limited peaks that rise above and beyond the more natural aquatic environment.  Those peaks rise up into a strange rarefied level of atmosphere—a level, not of water, but composed entirely of gases, nitrogen and oxygen.

As intelligent beings, we continue to confront the all too obvious evidence that “we are not alone.”  But I’m not talking about intelligent life on other planets.  “We are not alone” on our own planet.  The creatures around us have developed intelligence and self-awareness but, often, not “on our terms.”  These “others” have developed out of their own environmental and physiological roots.  Our planet is home to more and stranger environments (worlds) than we regularly or comfortably imagine.   It seems that intelligence and self-awareness are not a single, defined point at one end of a yard stick.  Rather, as Dr. Jennifer Mather of the University of Lethbridge suggests, intelligence and self-awareness may come “in flavors.”