A cephalopod passes a cognitive test designed for human children.

Cuttlefish have been given a new version of the marshmallow test, and the results may show there’s more going on in their strange little brains than we know.

Researchers say the cuttlefish’s ability to learn and adapt may have evolved to give it an edge in the eat-or-be-eaten marine world in which it lives.

marshmallow test or Stanford Marshmallow ExperimentIt’s very simple.

Place the child in the room with the marshmallows. We were told that if we didn’t eat the marshmallow for 15 minutes, we were given a second marshmallow and could eat both.

This ability to delay gratification demonstrates cognitive abilities such as future planning, and was originally conducted to study how human cognition develops. Specifically, at what age are humans smart enough to delay gratification if it means better results later?

Because it is so simple, you can adapt it to your animal. Obviously you can’t tell an animal that it will get a better reward if it waits, but you can train it to understand this. better If you don’t eat the food in front of you right away, it will come to you.

portion Primates can delay gratificationtogether dogAlthough inconsistent. Corvids also passed the marshmallow test.

In 2020, cuttlefish also passed their version of the marshmallow test. Scientists have discovered that the common squid (Sepia officinalis) You can refrain from eating crab meat in the morning once you know that your dinner is something you much prefer – shrimp.

However, a research team led by Alexandra Schnell, a behavioral ecologist at the University of Cambridge, pointed outIn this case, it was difficult to determine whether these changes in foraging behavior in response to prey availability were driven by the ability to exercise self-control.

So they designed another test on six common squid. The squid were placed in a special tank with two sealed chambers with transparent doors that allowed the animals to see inside. There were snacks in the room. One had the less desirable pieces of live crayfish, and the other had the much more attractive live grass shrimp.

The door also had symbols that the squid had been trained to recognize. A circle meant the door would open straight away. A triangle means that the door will open after a time interval between 10 and 130 seconds. And a square, used only under control conditions, means the door will remain closed indefinitely.

In test conditions, shrimp were placed behind an open door and live shrimp could only be accessed after a time delay. If the squid ate the shrimp, the shrimp were immediately removed.

Meanwhile, in the control group, the shrimp remained inaccessible behind a square symbol door that did not open.

The researchers found that all squid in the test condition decided to wait for their preferred food (live shrimp), but did not do so in the control group, which had no access to it.

“In the current study, the cuttlefish were both able to wait for a better reward and tolerate delays of up to 50 to 130 seconds, similar to what is seen in large-brained vertebrates such as chimpanzees, crows, and parrots.” Schnell said in 2021:.

Another part of the experiment was to test how well the six squid learned. Two visual cues were presented: a gray square and a white square.

As they approach one, the other is removed from the tank. If they made the “right” choice, they would be rewarded with a treat.

After learning to associate a square with a reward, the researchers switched the cues so that a different square was now the reward cue.

Interestingly, the squid that learned to adapt to these changes the fastest were also the ones that were able to wait longer for their shrimp reward.

Squids seem to be capable of self-control. That’s right. But the reason is not clear.

Delay of gratification in species such as parrots, primates, and crows has been linked to factors such as tool use. plan ahead), food caching (for obvious reasons) and social skills (because prosocial behavior – Benefits social species, such as providing food for everyone).

As far as we know, squid do not use tools, do not store food, and are not particularly social. Researchers believe the ability to delay gratification may be related to the way squid find food.

“Cuttlefish spend most of their time camouflaged, sitting and waiting, with brief periods of time foraging.” Schnell said at the time:.

“Because they break their stomachs when looking for food, they expose themselves to every predator in the ocean that wants to eat them. We speculate that delayed gratification may have evolved as a by-product of this, so the squid waits to select better quality prey. Food can be optimized.”

This is an interesting example of how very different lifestyles in very different species can result in similar behaviors and cognitive abilities.

Evidence of ‘episodic memory’ has been discovered in cuttlefish, and in 2024, scientists reported the first observations of the organism’s formation. false memory.

The research team noted that future research should determine whether squid can actually plan for the future.

The team’s research was published as: Proceedings of the Royal Society B.

A version of this article was first published in March 2021.