Cephalopods Have Passed a Cognitive Test Designed For Human Children

A test of the intelligence of cephalopods conducted back in 2021 served as further evidence of the significance of animal intelligence for humans.

A modified version of the marshmallow test was administered to cuttlefish, and the findings could show that their peculiar small brains are more complex than previously thought.

According to the researchers, cuttlefish may have gained an advantage in the competitive maritime environment they dwell in due to their capacity for learning and adaptation.

The Stanford marshmallow experiment, sometimes known as the marshmallow test, is a very simple experiment.

A marshmallow is placed in a room with a youngster. They are informed that they will receive a second marshmallow and be permitted to eat both if they can resist eating the first one for fifteen minutes.

It was initially done to investigate how human cognition develops, especially, at what age a person is smart enough to delay satisfaction if it meant a better outcome later. This capacity to delay gratification displays cognitive capacities such as future planning.

It's so easy to modify for animals because of its simplicity. You cannot, of course, tell an animal that waiting will result in a greater reward, but you may teach it that better food will be provided if it is not consumed right immediately.

Like dogs, certain primates can postpone satisfaction, but not always. The marshmallow test has been passed by corvids as well.

Additionally, cuttlefish passed an iteration of the marshmallow test in 2020. Researchers discovered that common cuttlefish (Sepia officinalis) may avoid eating crab meat in the morning if they know that shrimp will be their dinner of choice.

But as a group of scientists led by the University of Cambridge's Alexandra Schnell, a behavioral ecologist, pointed out, in this instance, it was challenging to figure out whether this shift in foraging behavior in response to the availability of prey was also controlled by the capacity for self-control.

Thus, they created an additional exam for six common cuttlefish. The cuttlefish were kept in a unique tank that featured two closed compartments with see-through walls that allowed the creatures to look inside. There were refreshments in the chambers, one containing a far more alluring live grass shrimp and the other a less desirable chunk of raw king prawn.

Additionally, the cuttlefish had been trained to recognize symbols on the doors. A circle indicated that the door would open immediately. A triangle indicated that the door will open in ten to one hundred thirty seconds. Furthermore, if a square was utilized exclusively under the control condition, the door would remain closed forever.

While the live shrimp was only accessible after a delay, the prawn was positioned behind the open door in the test condition. The shrimp was taken out right away if the cuttlefish tried to eat the prawn.

Concurrently, the square-symbol door in the control group remained closed, making the shrimp unavailable.

The cuttlefish in the test condition all made the decision to wait for their favorite food—the live shrimp—while the cuttlefish in the control group—where they were unable to obtain it—did not bother to do the same.

"Cuttlefish in the present study were all able to wait for the better reward and tolerated delays for up to 50-130 seconds, which is comparable to what we see in large-brained vertebrates such as chimpanzees, crows and parrots," Schnell said in 2021.

The six cuttlefish were tested for their ability to learn as the other component of the experiment. They were presented with a white and a gray square as two distinct visual signals.

The other would be taken out of the tank as they got closer to one, and if they chose the "right" one, they would receive a snack.

The researchers changed the cues such that the other square became the reward cue once the participants had become adept at associating a square with a reward.

Remarkably, the cuttlefish that were able to wait longer for the shrimp reward were also the ones that quickly learned to adjust to this shift.

Yes, it appears that cuttlefish are capable of exercising self control, although the reason for this is unclear.

Delay in gratification has been associated with tool use (because it necessitates planning ahead), food caching (for obvious reasons), and social competence (because prosocial behavior, like ensuring everyone has food, benefits social species), among other traits in species like parrots, primates, and corvids.

As far as we know, cuttlefish are not very sociable, nor do they utilize tools or hoard food. The capacity to postpone satisfaction, according to the researchers, may instead be related to how cuttlefish scavenge for food.

"Cuttlefish spend most of their time camouflaging, sitting and waiting, punctuated by brief periods of foraging," Schnell said at the time.

"When they forage, they disrupt their camouflage, leaving them vulnerable to any ocean predator out to devour them. We hypothesize that this led to the evolution of delayed gratification, which allows cuttlefish to maximize foraging by delaying the selection of higher-quality food."

It's an amazing illustration of how very different lives in very different animals may lead to identical cognitive capacities and behaviors.

The researchers concluded that more study has to focus on figuring out whether cuttlefish are really able to make plans for the future.

The team's research was published in Proceedings of the Royal Society B.