Monkeys can do math? Yes, say scientists

Monday, May 05, 2014 by: David Gutierrez, staff writer
Tags: monkeys, math, intelligence

(NaturalNews) Researchers from Harvard Medical School have shown that monkeys are capable of abstract addition, in a study published in the Proceedings of the National Academy of Sciences on April 21.

Studies have shown that many species of animals are capable of estimating relative quantities, such as which group contains more animals. This can also translate into slightly more abstract settings, such as identifying the larger of two clusters of dots. Chickens have been shown to be able to count as high as five and to understand the property of inference: that if A is greater than B and B is greater than C, then A must also be greater than C.

Fewer animals have demonstrated the ability to understand symbolic representations of quantity, such as numbers. Yet numbers are the foundation of human mathematics, in part because it is much easier to tell the difference between large quantities when they are represented symbolically. Like all animals, humans have a hard time telling which group of objects is larger as the number of items in each group increases; it's easier to tell the difference between two apples and four apples than to tell the difference between 22 apples and 24 apples.

"You would have trouble distinguishing 'oo o ooo ooo ooo ooo oo ooo' [a string of 20 symbols] from 'o ooo oooo oo oooo ooo ooo o' [a string of 21 symbols]," lead author Margaret Livingstone said, " but if I asked you whether 20 was larger or smaller than 21, you could answer faster and more accurately."

Symbolic math

Scientists have previously shown that some primates are able to learn that symbols can represent quantities and that two such symbols can be combined to represent an even larger quantity. In the current study, researchers sought to determine whether monkeys can make the leap from this understanding to actual addition.

The researchers taught three rhesus macaques that selecting one of 26 separate symbols always resulted in a reward of the same number (0-25) of drops of water, juice or orange soda. The symbols used were the Arabic numerals 0 through 9 and 16 distinct letters. The researchers found that when given a choice between two separate symbols, the monkeys selected the one that gave them a greater reward 90 percent of the time.

"The monkeys want the most of whatever is out there and this is just one of many ways to figure out the best way to get the most," Livingstone said.

The monkeys were then offered a choice between two separate pairs of symbols. The monkeys quickly learned to select the option with the greater sum, in order to get a bigger reward.

"They turned out to be like us -- more accurate when values were represented by symbols than by the number of dots," Livingstone said. "It tells us what good symbols are."

Adding, not memorizing

In order to make sure that the monkeys were not just memorizing and assigning values to pairs of symbols, the researchers repeated the experiment with a new set of 26 symbols. The monkeys were still able to pick the set of symbols with the greater sum, even under this new system - although their accuracy did go down, perhaps due to their lesser familiarity with the new symbols.

"The monkeys did not memorize the addition of pairs of numerals; they just fairly accurately combined two symbols," Livingstone said.

The findings suggest that the capacity for math in human beings may be ancient indeed, as the ape (human) and old-world monkey lineages diverged 25 million years ago.

Next, the researchers hope to see if they can teach the monkeys to multiply.

(Natural News Science)

Sources for this article include:
http://www.livescience.com/44986-monkeys-do-math.html
http://www.natureworldnews.com
http://phys.org/news/2014-04-rhesus-monkeys-reward.html
http://www.newscientist.com
http://www.natureworldnews.com