BIOLOGISTS HAVE LONG NOTED the similarities between the eyes of an octopus and the eyes of a human. Canadian zoologist N. J. Berrill called it “the single most startling feature of the whole animal kingdom” that these organs are nearly identical: both animals’ eyes have transparent corneas, regulate light with iris diaphragms, and focus lenses with a ring of muscle.
Scientists are currently debating whether we and octopuses evolved eyes separately, or whether a common ancestor had the makings of the eye. But intelligence is another matter. “The same thing that got them their smarts isn’t the same thing that got us our smarts,” says Mather, “because our two ancestors didn’t have any smarts.” Half a billion years ago, the brainiest thing on the planet had only a few neurons. Octopus and human intelligence evolved independently.
“Octopuses,” writes philosopher Godfrey-Smith, “are a separate experiment in the evolution of the mind.” And that, he feels, is what makes the study of the octopus mind so philosophically interesting.
The octopus mind and the human mind probably evolved for different reasons. Humans — like other vertebrates whose intelligence we recognize (parrots, elephants, and whales) — are long-lived, social beings. Most scientists agree that an important event that drove the flowering of our intelligence was when our ancestors began to live in social groups. Decoding and developing the many subtle relationships among our fellows, and keeping track of these changing relationships over the course of the many decades of a typical human lifespan, was surely a major force shaping our minds.
But octopuses are neither long-lived nor social. Athena, to my sorrow, may live only a few more months — the natural lifespan of a giant Pacific octopus is only three years. If the aquarium added another octopus to her tank, one might eat the other. Except to mate, most octopuses have little to do with others of their kind.
So why is the octopus so intelligent? What is its mind for? Mather thinks she has the answer. She believes the event driving the octopus toward intelligence was the loss of the ancestral shell. Losing the shell freed the octopus for mobility. Now they didn’t need to wait for food to find them; they could hunt like tigers. And while most octopuses love crab best, they hunt and eat dozens of other species — each of which demands a different hunting strategy. Each animal you hunt may demand a different skill set: Will you camouflage yourself for a stalk-and-ambush attack? Shoot through the sea for a fast chase? Or crawl out of the water to capture escaping prey?
Losing the protective shell was a trade-off. Just about anything big enough to eat an octopus will do so. Each species of predator also demands a different evasion strategy — from flashing warning coloration if your attacker is vulnerable to venom, to changing color and shape to camouflage, to fortifying the door to your home with rocks.
Such intelligence is not always evident in the laboratory. “In the lab, you give the animals this situation, and they react,” points out Mather. But in the wild, “the octopus is actively discovering his environment, not waiting for it to hit him. The animal makes the decision to go out and get information, figures out how to get the information, gathers it, uses it, stores it. This has a great deal to do with consciousness.”
So what does it feel like to be an octopus? Philosopher Godfrey-Smith has given this a great deal of thought, especially when he meets octopuses and their relatives, giant cuttlefish, on dives in his native Australia. “They come forward and look at you. They reach out to touch you with their arms,” he said. “It’s remarkable how little is known about them . . . but I could see it turning out that we have to change the way we think of the nature of the mind itself to take into account minds with less of a centralized self.”
“I think consciousness comes in different flavors,” agrees Mather. “Some may have consciousness in a way we may not be able to imagine.”
