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Having the opportunity to wait for better food, cuttlefish – flexible sea creatures similar to octopuses and squid – showed self-control associated with the higher intelligence of primates.
This was part of an experiment by Alex Schnell of the University of Cambridge and colleagues.
“What surprised me the most was that the level of self-control shown by our cuttlefish was quite advanced,” she told Lulu Garcia-Navarro. Weekend edition.
The experiment was essentially a look at the classic “marshmallow” experiment of the 1960s. In this experiment, young children were introduced to a marshmallow and told that if they could resist eating it unattended for a few minutes, they would receive two marshmallows. But if they eat it, that’s all they get.
It is generally believed that children who can slow down satisfaction do better on tests and are more successful later in life. (There are, of course, many caveats when it comes to human experiments.)
To adapt the cuttlefish experiment, the researchers first invented the cuttlefish’s favorite food: live grass shrimp; and their second favorite food: a piece of king prawn. Instead of choosing one or two marshes, the cuttlefish had to choose either their favorite food or their second favorite food.
“Each of the food items was placed in clean chambers in its tank,” says Schnell. “One chamber opened immediately, while the other chamber opened only after a delay.”
It “essentially tests whether they can resist the temptation of their second preferred food product and wait for their preferred food product.”
The cuttlefish learned to wait.
“Animals like rats, chickens and pigeons find it difficult to resist temptation and have relatively lower levels of self-control, waiting only a few seconds,” says Schnell. “While animals such as chimpanzees, crows and parrots, they show more advanced self-control and can wait up to a few minutes. And cuttlefish in our study waited between 50 and 130 seconds.”
Animals that are able to exercise self-control in this way have advantages. For example, animals may hide food to eat later, but they must resist the urge to eat now.
The researchers say the experiment is the first evidence so far for this type of cognitive ability in invertebrates.
In cuttlefish, Schnell believes that delayed gratification is related to their lifestyle. They are masters of camouflage; they are able to blend into their environment and can remain completely still for long periods of time to avoid predators.
Then they look for food for short trips. “People who wait for better prey can eat more efficiently while limiting their exposure to predators,” Schnell wrote.
But to take things a step further, the researchers did a second experiment. They placed colored markers in the tank and taught the cuttlefish to associate a particular colored marker with food by releasing food when the cuttlefish went to the marker. Then they exchanged colors.
The second experiment was to test the “success” of the animals. Cuttlefish, who learned to connect and associate food markers more quickly, were considered better students.
They found that cuttlefish, which manage to slow down the satisfaction, turn out to be the ones that are better at learning. This is “the first demonstration of a link between self-control and the effectiveness of training outside primate genera,” Schnell wrote.
Finding these similarities between cuttlefish and primates “is an important part of the evolutionary puzzle,” she added.
Therefore, soft cuttlefish leads scientists one step closer to understanding more about the origins of intelligence.
Rosemary Misdari and Martha Ann Overland produced and edited the audio interview.