Cuttlefish Pass A Psychological Test Given To Children


| LAST UPDATE 08/16/2022

By Sharon Renee
Cuttlefish Marshmallow Test Experiment
Ullstein Bild via Getty Images

Delaying gratification is a difficult skill that, can be achieved not only by humans but apparently by species. One of the highly regarded psychological tests evaluating this trait is the Stanford Marshmallow Test, which was published by Prof. Walter Mischel in 1972. In short, the study involved children who were offered a marshmallow, but were told if they could wait for the treat, they'd receive two of the item.

Cuttlefish Marshmallow Experiment Smart
Ullstein Bild via Getty Images

The Marine Biological Laboratory (MBL) of the University of Chicago decided to try the test on Cuttlefish; a marine mollusk. “We used an adapted version of the Stanford marshmallow test, where children were given a choice of taking an immediate reward (1 marshmallow) or waiting to earn a delayed but better reward (2 marshmallows),” Alexandra Schnell of University of Cambridge, who was in residence as a publisher, writes. “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.”

Cuttlefish MBL Marshmallow Test
Jeff Greenberg via Getty Images

The study was conducted by presenting Cuttlefish candidates with two different food options behind clear walls. One showed raw king prawn, and the other their preferred food of live grass shrimp. The cuttlefish in the study were trained overtime to comprehend which light-up symbols meant the chamber doors would open right away, after a delay, or not open at all. If the prawn door opened right away and the cuttlefish ate it, the shrimp option was taken away. If the prawn door opened and the cuttlefish left it alone, they eventually were given the chance to eat the shrimp.

Cuttlefish Psychological Marshmallow Test
The Washington Post via Getty Images

Having the researchers nearly dumbfound with the trait the invertebrates exhibited, reasons hypothesizing the findings arose. Schnell shed light on the agreed theory the scientists concluded with: “Cuttlefish spend most of their time camouflaging, sitting and waiting, punctuated by brief periods of foraging,” she explains. “They break camouflage when they forage, so they are exposed to every predator in the ocean that wants to eat them. We speculate that delayed gratification may have evolved as a byproduct of this, so the cuttlefish can optimize foraging by waiting to choose better quality food.”

Advertisement - Continue Reading Below
Cuttlefish Marshmallow Test Successful
Ullstein Bild via Getty Images

Putting Cuttlefish in the ranks of big-brained mammals such as Chimpanzees and Dolphins, it can be agreed that the study was exceptionally surprising. The MBL suggests that researching cognitive behaviors outside of the primate world can unlock key mysteries in evolution. More from the study can be found right here.