Is a small octopus less intelligent than a large one?

Sorry to be late to the party, but when this thread was first posted I knew had recently seen something very interesting online somewhere about octopus intelligence, but I just could not remember where. I just now stumbled across it again:
Thinking like an octopus
About half of an octopus’ nervous system is is in its tentacles, so it is almost as though it has 9 separate brains.

That sounds entirely reasonable and balanced (and actually, I don’t disagree after all) - thanks for sharing it.

Why is the narrator in that video talking like he’s addressing a room filled with special needs children?

Doesn’t have to be special needs. That level of discourse sounded fine for younger kids, maybe 6 or so years old. I assume Natl Geographic occasionally produces shows for kids.

Are you assuming that Neanderthals were not more intelligent than we are? Is there a good reason to believe this?

A similar, albeit different story, with an actual cite ! Otto the octopus learned how to disable electric lights that bothered him by shorting the power to the whole aquarium.

OK, so the critter’s actual thinking process probably didn’t involve anything more complex than “I wish that light would piss off so I’ll use a skill of mine that makes stuff piss off on that light”, but still.

Lol, from that same article:


They really need to take a video of that.

Although it is difficult to compare the intelligence of different species, much less phyla, I would contend that most species of octopuses, as well as many squid and cuttlefish species, are substantially more capable of mechanical problem-solving skills than any mammal except for the apes and ursines, certainly far more than canids and felids. As njtt notes, the nervous system of the octopus is far more distributed than in vertebrates, so many of the control and feedback functions that are located in discrete cortices in mammals don’t exist in the cephalopod brain structure, and therefore a direct comparison between brain/body mass ratios between vertebrates and octopuses is not a very useful metric for intelligence. By the way, the “head” of an octopus is actually mostly its organ sac; the actual brain is located somewhat between and below the eyes and is about the size of a walnut in the largest species.

Octopus do lack a high degree of social intelligence as they are mostly solitary creatures, though they can communicate with each other in at least a rudimentary fashion via flashing chromatosphores and body movement. Octopuses are oviparous, and while the female does often live through the hatching of the offspring in most species, she doesn’t consume food during their development and dies soon after, contributing nothing to the rearing of offspring, so unlike the more intelligent species of mammals and aves there is no extend period of training and grooming.

Indeed. On a couple of occasions while diving I’ve “made friends” with curious octopuses who will then reach out and grab my glove or forearm with their tentacles, often climbing up my arm. While the beak is a vicious-looking thing that can shear through soft tissue like a knife through butter, the octopus rarely if ever uses the beak in a defensive fashion, as damage to it will render it incapable of eating and therefore death. Octopuses are generally not aggressive with divers (unlike some species squid, which will attack divers in swarm), but in their curiosity they may do things that are alarming, like pulling off a mask, pulling at the regulator, or trying to climb inside the BCD or a catch bag to explore. I gentle burst of air from the regulator mouthpiece is usually enough to spook them back; trying to unwind one from your arm, on the other hand, often makes them clutch harder, which is again alarming but general harmless.

As for the relative intelligence of octopus species I don’t know of any definitive work on the topic. Most of what I’ve read is focuses on intelligence of just a few species like the Common Octopus (Octopus vulgaris and the Giant North Pacific Octopus (Enteroctopus dofleini). There use to be octopus “wrestling” competitions in which divers would collect and bring these beasts to the surface, so they’re clearly not that hazardous.


You have a rather nightmarish definition of “harmless”…

I totally want to see Otto the Octopus juggling hermit crabs. Pretty please, Santa? :smiley:

Octopuses are curious animals. If you let them satisfy their curiosity they won’t do any real harm. (A trained diver should be able to deal with a dislodged mask or regulator without panic; if you can’t or are not equipped with a spare second stage or mask, you shouldn’t be diving.) Where divers get into trouble with octopus is when they try to start fighting the creature, which instinctively responds by either trying to cling harder or release ink.