Back in 2021, a test of cephalopod smarts highlighted how important it is for us humans not to underestimate animal intelligence.
A new version of the marshmallow test was put to cuttlefish, and the results may show there’s more going on in their strange little brains than we knew.
Researchers said the cuttlefish’s ability to learn and adapt may have evolved to give them an edge in the cutthroat marine world they live in.
marshmallow test etc. Stanford marshmallow experimentvery simple.
The child is placed in a room with marshmallows. They are told that if they can go 15 minutes without eating a marshmallow, they will receive a second marshmallow and can eat both.
This ability to delay gratification is indicative of cognitive abilities such as future planning, and was originally done to study how human cognition develops. Specifically, it’s the age at which humans are smart enough to postpone gratification when they can get better results later.
It is simple and can be adjusted to suit the 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 that. better If you don’t eat the food in front of you quickly, the food will come.
some Primates can delay gratificationwith dogalthough it is contradictory. The crow also passed the marshmallow test.
In 2020, squid also passed a version of the marshmallow test. Scientists have discovered that the common squid (sepia officinalis) If you learn that dinner is something you like more – shrimp, you can refrain from eating crab meat in the morning.
However, a team of researchers led by Alexandra Schnell, a behavioral ecologist at the University of Cambridge, pointed outIn this case, it was difficult to determine whether changes in foraging behavior in response to prey availability were also governed by the ability to exert self-control.
So they designed another test involving six common squid. The cuttlefish were kept in a special aquarium with two sealed chambers with transparent doors so the animals could see inside. There were snacks in the room. One had raw shrimp, which I didn’t really like, and the other had live grass shrimp, which was much more appealing.
The door also had a symbol painted on it that the squid was trained to recognize. A circle means the door will open immediately. The triangle means the door will open after a time interval of 10 to 130 seconds. And the rectangle used only in the control condition means the door will remain closed indefinitely.
In the test condition, shrimp were placed behind an open door and live shrimp could only be accessed after a short delay. When the squid targeted the shrimp, the shrimp were quickly removed.
Meanwhile, in the control group, the shrimp remained inaccessible behind a door with a square symbol that would not open.
The researchers found that under the test conditions, all the squid decided to wait for their preferred food (live shrimp), but did not bother to do so in the control group, which had no access to food.
“All the squids in this study were able to wait for a better reward and tolerate delays of up to 50 to 130 seconds, which is similar to what is seen in large-brained vertebrates such as chimpanzees, crows, and parrots. It is equivalent to that.” Schnell said in 2021..
Another part of the experiment was testing the six squid’s learning abilities. They were shown two different visual cues: a gray square and a white square.
When they approached one, the other was removed from the tank. If they make the “right” choice, they are rewarded with a snack.
Once the researchers learned to associate the square with the reward, they switched the cues so that the other square became the reward cue.
Interestingly, the squid that learned to adapt to this change fastest were also the ones that were able to wait longer for the reward shrimp.
Squids seem to be able to exhibit self-control, but it’s unclear why.
In species such as parrots, primates, and corvids, delay of gratification is thought to be associated with factors such as tool use. plan ahead), food cache (for obvious reasons) and social skills (because prosocial behavior – such as making sure everyone has food – which benefits social species).
As far as we know, cuttlefish do not use tools or hide food, and are not particularly social. Researchers think this ability to delay gratification may have something to do with the way squid find food.
“Cuttlefish spend most of their time camouflaging, sitting and waiting, interrupted by short foraging periods.” Schnell said at the time..
“Squids break their camouflage when foraging, exposing them to any predators in the ocean that might want to eat them. We speculate that delayed gratification may have evolved as a byproduct of this. Therefore, cuttlefish can optimize their foraging by waiting to select better quality food. “
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-like memory” has been discovered in squid, and in 2024 scientists reported the first observations of this creature’s formation. false memory.
The researchers noted that future studies will need to find out whether squid can actually plan for the future.
The team’s research Proceedings of the Royal Society B.
A version of this article was first published in March 2021.
