Birds have self control—just like humans, according to new research that found Eurasian jays can resist a tempting snack when they know waiting will bring an even better one.
The study was actually inspired by the 1972 ‘Stanford Marshmallow’ test in which a US psychologist offered children a choice of one immediately—or two if they waited.
All kinds of unique human cognitive traits have been demonstrated in birds. From tool use to understanding the concept that zero can represent something and nothing at the same time (more on that rather complex explanation here).
These are particularly found in corvids, which include crows, jays, magpies, and ravens, a group sometimes called “feathered apes.”
This time, when the jays in the study were presented with mealworms, cheese, or bread, their first, second, and third favorite foods, all the birds tested passed the challenge by ignoring the immediately available treat until a screen was raised to allow access to the preferred choice.
One particularly bright bird ‘JayLo’, ignored a piece of cheese and waited a full five-and-a-half-minutes for a mealworm.
“In multiple trials, I sat there watching JayLo ignore a piece of cheese for over five minutes. I was getting bored, but she was just patiently waiting for the worm,” said Dr. Alex Schnell, of the University of Cambridge. “It is just mind-boggling that some jays can wait so long for their favorite food.”
The most intelligent birds, determined by separate intelligence tests, did best when a range of delay times tested their perseverance, linking their self-control to brainpower in the authors’ minds.
The worst performers, ‘Dolci’ and ‘Homer’ could only manage a maximum of 20 seconds.
The authors detail that the birds looked away from the bread or cheese when it was presented, as if to distract themselves on purpose. Similar behavior has been seen in chimpanzees and children.
The jays also adjusted behavior according to circumstances. When the worm was visible but always out of reach, they always ate the bread or cheese.
And the length of time they were willing to wait for the worm fell if it was pitted against their second most preferred food as the immediate treat, compared to their third.
This flexibility shows jays only delay gratification when it’s warranted.
There’s good evolutionary biology to back this behavior up, and it’s not just a case of general brainiacsmanship.
Corvids hide, or ‘cache’, food to save it for later. In other words, they need to be able to delay immediate gratification to plan for meals. It may have driven self-control in these birds, as well as underpinned decision making and planning, and fueled intelligence in other animals that cache and plan such as humans, chimpanzees and fish.
The results, published in Philosophical Transactions of the Royal Society B, show the link exists across distantly related animal groups—suggesting it has evolved independently several times.