The smart can wait: Humans and some animals are known to resist immediate temptation if they know there is an opportunity for greater gain. In birds, too, there is a connection between the individual ability for self-control and intelligence, according to a study of jays: particularly self-controlled specimens perform best in intelligence tests. The results suggest that self-control is a fundamental trait of cognition in highly evolved creatures, the researchers say.
The ability to anticipate behavior is particularly pronounced in humans: It is well known that resisting a tempting impulse can lead to better results. In contrast, most animals are unable to resist an immediate food stimulus or lack the cognitive abilities to understand that waiting makes sense. But as research has now shown, some smart species are exceptions: primates, birds like parrots, and even the clever squid can seem to grasp the advantage and hold back, studies show.
In the case of humans, research shows that the individual's capacity for self-control is linked to general intelligence. Something similar has also been proven with our closest relatives in the animal kingdom – the chimpanzees: the more intelligent, the more self-controlled an individual is. Interestingly, the scientists led by Alexandra Schnell from the University of Cambridge have already discovered evidence in the squid that an individually high ability for self-control is associated with other particularly good cognitive performances of these marine animals. In the current study, Schnell and her colleagues have now carried out investigations on representatives of the corvids: the jays (Garrulus glandarius), which are already considered to be very clever.
Jays are disciplined
The team conducted experiments on ten specimens to assess their ability to exercise self-control or delay gratification. The temptations were mealworms, bread and cheese. The worms are particularly popular, with bread and cheese coming in second and third place, depending on the individual preferences of the animals. A mechanism was used in the experiments in which the birds were offered bread or cheese while a mealworm could be seen behind a Plexiglas pane. The special treat became accessible only when the animals forgo the readily available food and waited a period of time. As the researchers report, all of the test animals understood this connection after the training phase: they were able to resist consumption of the moderately attractive food for a certain time frame in order to wait for the preferred food.
The researchers finally explored how long the animals could control themselves in this way. There was a considerable individual range: The leader was the jay lady “JayLo”, who ignored the less attractive food for a remarkable five and a half minutes in order to wait for the mealworm. The worst participants, "Dolci" and "Homer", on the other hand, could only control each other for a maximum of 20 seconds. "It's amazing that some jays can wait so long for their favorite food," Schnell emphasizes. It also showed that the waiting time tolerated was dependent on gain: the time an animal was willing to wait for the worm decreased when competing with the second favorite food as an immediate reward compared to the third favorite. The researchers also observed another interesting behavior: the jays would turn away from the bread or cheese — as if to distract them from the temptation.
Correlation with general intelligence
The jay has thus now emerged as another decidedly 'disciplined' animal. But the study went beyond this result: The researchers also carried out "intelligence tests" with their test animals. They set the jays different cognitive tasks that are commonly used to measure general intelligence. First of all, it became apparent: “The performance of the birds varied significantly from individual to individual – some did very well on all tasks, others were only mediocre. When a bird did well on one task, it did well on all the other challenges as well—suggesting that an overall intelligence factor underlies their performance,” Schnell says. However, the comparison with the results of the self-control tests was particularly interesting: The researchers report that the performance in these tasks correlated significantly with the ability of the respective jay to wait for better opportunities.
According to them, this is the first evidence of a connection between self-control and intelligence in birds. Against the background of the findings in humans and chimpanzees as well as the indications in the squid, it is now clear that the connection between cognition and self-control also exists in only distantly related groups of animals, which indicates that it has evolved independently several times, the researchers conclude Scientist.
Source: University of Cambridge, professional article, Philosophical Transactions of the Royal Society B Biological Sciences, doi: 10.1098/rstb.2021.0348