Enter, then, the comparative psychologists.
Nicola Clayton didn’t start out studying cuttlefish. A professor at Cambridge, she has built her career around the remarkable behavior of the scrub jay, a small blue-black bird that stores food for later. In 1998, she and colleagues showed that the birds can remember how long it’s been since they hid food items. They can plan for the future, hiding food in places where they have reason to believe they’ll be hungry later.
Their behavior is more sophisticated than simply learning that food will appear if you push a button or recognize a pattern, something that many animals can do. Apart from apes and other corvids, like crows, few animals studied so far possess the full portfolio of mental abilities demonstrated by these birds.
But cuttlefish and other cephalopods may be an intriguing test case. When octopus and cuttlefish hunt, they do not take the same route two days in a row, marine biologists have observed. Christelle Jozet-Alves, a comparative psychologist, wondered if that meant they had a memory like that of corvids, capable of re-experiencing what had happened to them in the past. In 2013, with Dr. Clayton and a collaborator, she published a tantalizing cuttlefish study suggesting they did. Dr. Clayton, Dr. Schnell and their colleagues have started to ask: Do cuttlefish have a sense of the future and the recent past? Can they make decisions about what they think is likely to happen in the future?
Octopuses have long amazed observers with their apparent canniness — in one YouTube clip with more than 2 million views, an octopus scoops up coconut shells and carts them off, perhaps to use them later as tools. Squids also have large brains and sophisticated behavior. But cuttlefish are easier to grow in the lab than squid and easier to work with than octopuses, which are often standoffish and may refuse to engage with an experimenter, Dr. Schnell said.
There is, of course, the Houdini factor, too.
“You get little escape artists with octopuses. You come in in the morning and it doesn’t matter how tight you have closed an aquarium tank, you’ll find them crawling out,” she said.