Mathemagicians of the animal kingdom

While plenty of people are quick to avoid arithmetic by stating that they’re “not a math person,” broader looks at the animal kingdom make it clear that Homo sapien really is a math-oriented species. While not all of us made it through Calculus I, we actually use quantitative reasoning so often we don’t recognize it as special. It may be easier to see when surveying other animals’ quantitative limits, which in many cases end at counting.

Counting as a canine

Counting objects is nothing to sneeze at though. While domestic dogs are capable of many interesting cognitive feats, they haven’t been found to be able to do more than binary assessments of quantities. Attempts to test their ability to count dog treats revealed that they could only reliably grasp the difference between zero and any other quantity of food. Since this is a smaller counting ceiling than has been observed in wolves, it’s assumed that domestication has somehow bred this ability out of our canine companions. Human breeders didn’t select for math skills because we didn’t really need it in our dogs.

Calculating your cohort

There are plenty of scenarios were basic headcounts are of use to wild species. Lions will listen to the roars of territorial rivals, and only pursue them if it sounds like they’ll encounter a smaller group. So a group of five lions will investigate the sound of three lions roaring, but not vise versa. The sounds of five or six rival lions seems to be the cap on this kind of intelligence gathering, but some of that may be due to the sources of the sounds being harder to decipher in larger groups.

If territory is important enough to count, then finding a mate definitely qualifies as a reason to keep some kind of mental tally as an animal. Pacific tree frogs (Pseudacris regilla) resemble many of their neighbors, and differentiate each other to mates through their croaking. Females are then tasked with keeping a count of pulses in males’ croaks to ensure they’re pursuing an appropriate bachelor, being specific up to phrases 10 notes long.

Abstraction and arithmetic

Some birds can take this all even further. Beyond counting crows and robins, an African gray parrot named Alex was able to listen to instructions and count specific sub-sets of objects, repeating back their sums. Alex lived for 30 years with Irene Pepperberg, an animal psychologist, and could communicate in a number of ways by the time he died in 2007. If given four sets of blocks of various colors, he could correctly count a specific subset of those blocks, such as “five green balls,” filtering out the red balls and green squares. However impressive these math and language skills were, Alex still seemed to be limited to a count of six.

Some of the most impressive non-human math skills have, unsurprisingly, been seen in our closest genetic relatives, chimpanzees. Chimps have been trained to not only have a grasp of quantities, but also further layers of abstraction and manipulation of those quantities, especially when reading and language skills were added to their training. A chimp named Ai was able to see pictures of dots, count them and then respond by pressing the corresponding Arabic numeral on a keyboard, such as “2” or “5.” When offered chocolates in two sets of bowls, chimps are also able to correctly add the competing quantities and pick the larger sum 90% of the time.

While picking “more chocolate” might not seem like a big leap from dogs picking something over nothing, it actually requires a lot of thought. First, the items must be accurately counted, and those quantities need to be somehow saved in the chimp’s memory. They then must be added, requiring the chimp to create a new number in it’s head, and then the two sums need to be compared. We can take this for granted, but it’s only because our brains and upbringing generally help us develop these abilities (just ask your average human 4-year-old.) Clearly quantitative analysis has been present in the animal kingdom for a long time based on how widespread it is. We’ve just pushed it farther, possibly by coupling it with language and more abstract thinking.

Source: The animals that have evolved the ability to count by Katie Silver, BBC Earth