An animal study revealed that brain size plays a major role in displaying self-control and self-restraint, according to a team of University researchers.

This study, conducted on 36 species of mammals ranging from orangutans to zebra finches, is the first large-scale investigation into the evolution of self-control. Study authors found that chimpanzees had more self-control than foxes and squirrels. They also found that brain size has a lot to do with the level of self-control these animals displayed.

The researchers noted that species with larger brain volume had more superior cognitive powers than species with larger body size. Additionally, species that were not particular about what they included in their diet showed better self-restraint.

Findings of the new study debunk previous statements that suggest "relative" brain size is a more accurate predictor of intelligence than "absolute" brain size.

Species included in the study were bonobos, chimpanzees, gorillas, olive baboons, stump-tailed macaques, golden snub-nosed monkeys, brown, red-bellied and aye-aye lemurs, coyotes, dogs, gray wolves, Asian elephants, domestic pigeons, orange-winged amazons, Eurasian jays, western scrub jay, zebra finches and swamp sparrows.

One experiment included training big and small creatures to access food inside a cylinder through a side entrance. In the first part of the experiment, researchers placed food items in an opaque cylinder and trained the creatures to gain access to the food by entering the cylinder through a side entrance. Once the creatures grew familiar with how to enter the cylinder, the food was moved to a transparent cylinder.

Researchers wanted to observe whether the animals would directly dash into the cylinder to grab the food or will use the previously learnt technique to enter the cylinder and eat the food.

The results showed that gorillas and other large-brained animals utilized the previously learnt technique to attain the "bait." The smaller brained animals showed mixed results.

"About half of the squirrels and gerbils did well and inhibited the direct approach in more than seven out of 10 trials," UC Berkeley doctoral student Mikel Delgado said in a statement. "The rest didn't do so well."

Another test included placing three cups (A, B and C) in a row with food in one of the cups (usually cup A). At first the animals were allowed to see which cup the food was placed in. After a while the cups were turned upside-down and the animals were made to identify which cup contained the food. If an animal could tap the correct cup three times, it proceeded to the next round. In the next round, the food was moved from cup A to cup B.

"The question was, would they approach cup A, where they had originally learned the food was placed, or could they update this learned response to get the food from a new location?" Delgado said. "The squirrels and gerbils tended to go to the original place they had been trained to get food, showing a failure to inhibit what they originally learned."

The study authors went on to highlight a possible explanation as to why species with bigger brains had better self-control. The researchers assume that because bigger brains can accommodate more number of neurons, the brain becomes more modularized, facilitating the development of "new cognitive networks."

Researchers said that this experiment also delivers a useful message to humans too recommending people should stop and think for a while before making any decisions or snatching a reward.

Findings of the study were published online in the Proceedings of the National Academy of Sciences.