It was rather a jolt to discover how smart octopuses are. Not only do we find them hard to relate to, they challenge our understanding of intelligence. We’ve already seen that crows can be as smart as apes, though their brains are organized quite differently. If intelligence does not derive from a specific type of brain structure, what is its origin?
We sometimes assume that reptiles cannot be as smart as mammals because they are exothermic (cold-blooded) rather than endothermic (warm-blooded), and the brain is a high metabolic area. Here, though, we find some surprises.
Reptiles lack some brain structures found in mammals but they can use what they’ve got for behavior that we would describe as intelligent: Crocodilians (alligators and crocodiles) have been reported to use sticks as decoys, play, and work in teams.
Exothermy slows intelligence but does not absolutely prevent it: Anole lizards were found as capable as tits (birds) in a problem-solving test for a food reward. But the anoles, being exothermic, don’t need much food — which, of course, hinders research.
Even fish have shown signs of what seems like intelligence. We are told that pairs of rabbitfishes “cooperate and support each other while feeding”:
While such behaviour has been documented for highly social birds and mammals, it has previously been believed to be impossible for fishes. … “We found that rabbitfish pairs coordinate their vigilance activity quite strictly, thereby providing safety for their foraging partner,” says Dr Simon Brandl from the ARC Centre of Excellence for Coral Reef Studies. “I’ve got your back: Fish really do look after their mates” at ScienceDaily
In 2009, evolutionary biologist Giacomo Bernardi was able to film a fish intentionally using a rock as a tool:
An orange-dotted tuskfish uncovered a clam buried in the sand, picked up the mollusk in his mouth, and carried it to a large rock 30 yards away. Then, using several rapid head-flicks and well-timed releases, the fish eventually smashed open the clam against the rock. In the ensuing 20 minutes, the tuskfish ate three clams, using the same sequence of behaviors to open them… And it’s more than tool use. By using a logical series of flexible behaviors separated in time and space, the tuskfish is a planner. This behavior brings to mind chimpanzees’ use of twigs or grass stems to draw termites from their nests. Or Brazilian capuchin monkeys who use heavy stones to smash hard nuts against flat boulders that serve as anvils. Or crows who drop nuts onto busy intersections and then swoop down during a red light to retrieve the fragments that the car wheels have cracked open for them. Jonathan Balcombe, “Fish Can Be Smarter Than Primates” at Nautilus
All the life forms discussed above are vertebrates except one. The smart octopus, like the coconut octopus featured below, is not only exothermic but an invertebrate. Its massive neural hardware has, we are told, “little in common with” the mammalian design. And, to deepen the mystery, the nautilus, also a mollusc, is the octopus’s stupid cousin, that is, it is just like other molluscs. So even common descent does not seem to be nearly as useful an explanation for differences in animal intelligence as we might have expected.
The narrator of the Smithsonian video assumes that the coconut octopus is uniquely intelligent. But we should keep in mind that most animal intelligence discoveries are comparatively recent and most of the ocean remains unexplored. For now, we can say that there are rough general trends in intelligence as in evolution, but they appear to be patterns, not laws. For example, endotherms like mammals and birds, who can maintain a fixed internal temperature, may be able to exhibit intelligent behavior more often (that was the lesson or the birds vs. the anoles), not more intelligent behavior as such.
All this bears on the question of making machines intelligent. What is it that we want machines to be and do under our guidance that these—often seemingly strange—life forms are and do spontaneously? The life forms do those things to stay alive. Does it matter then that machines are not alive? Stay tuned.
Note: Here we are concerned with intelligence seen as problem-solving. Whether reptiles, for example, experience emotions like love or whether various animals—whales, for example—have personality traits like those of humans are interesting but separate questions. They may bear on whether machines can have personalities.
See also: Is the octopus a “second genesis” of intelligence?
Furry, feathery, and finny animals speak their minds. Listen.