Pre-verbal number sense common to monkeys, babies, college kids

February 13, 2009,

Basic arithmetic and "number sense" appear to be part of the shared evolutionary past of many primates; it's the use of language to explain abstractions that apparently takes human math to a higher level.

Elizabeth Brannon, an assistant professor of psychology and neuroscience at Duke University, studies how human adults and infants, lemurs, and monkeys think about numbers without using language. She's looking for the brain systems that support number sense and trying to figure out how this cognitive skill develops.

"Number is one of the more abstract domains of cognition: three coins and three loaves of bread are very different concepts," says Brannon, who appears on a Friday afternoon panel at the AAAS annual meeting called "Comparative Cognition: The Science of Mental Evolution. "Yet, many studies show that babies, even in the first year of life, can tell the difference between quantities."

She runs about 500 babies per year through her testing lab at Duke, as well as macaques, lemurs and the odd undergraduate. Most of the experiments involve computer touch-screens and sets of brightly colored dots.

After seeing the same number of objects repeated in different-looking sets, infants recognize the novelty of a new number of objects. So do macaques. And both college kids and macaques can do a rough sort of math by summing sets of objects without actually counting them. Their speed and accuracy are about the same, in fact.

That the evolved brain has some fundamental sense of number without language should come as little surprise, Brannon says.

"There are all sorts of reasons why number would be useful for nonhuman animals in the wild. In foraging situations animals need to make decisions about how long to stay in a given patch of food and when to move on," Brannon says. "Territorial animals may need to assess the number of individuals in their own group relative to competing groups to decide whether to stand their ground or retreat."

Understanding the biological basis of our number sense might also help early childhood educators.

Brannon's latest work is aimed at understanding how the human brain changes to accommodate symbolism as a child learns the names of numbers and begins to grasp more abstract manipulations. "If the nonverbal number sense is really providing a critical foundation for math achievement, then this will suggest teaching methods that provide more grounding in the nonverbal quantity system."

Brannon is also exploring the macaque's sense of an empty set, what we'd call zero with our linguistically intensive sense of number. The monkeys are more likely to confuse an empty set with a 1 or a 2 than they are to confuse it with an 8 or a 9, she says, which shows they're putting zero in the proper place on the number line.

"We're trying to understand how the animal mind works. How much of human thought is dependent on language?"

Source: Duke University

Explore further: Bioengineered soft microfibers improve T-cell production

Related Stories

Bioengineered soft microfibers improve T-cell production

January 18, 2018

T cells play a key role in the body's immune response against pathogens. As a new class of therapeutic approaches, T cells are being harnessed to fight cancer, promising more precise, longer-lasting mitigation than traditional, ...

New technology for diagnosing immunity to Ebola

January 15, 2018

A promising new approach to detect immunity to Ebola virus infection has been developed by researchers from i-sense in a collaboration between UCL and Imperial College London.

Asocial media

January 19, 2018

The incidence of abusive commentary on social media is rising. Media specialists Carsten Reinemann and Christoph Neuberger are exploring the grounds for this development, and have invited journalist Dunja Hayali to discuss ...

Hunter-gatherers have a special way with smells

January 18, 2018

When it comes to naming colors, most people do so with ease. But, for odors, it's much harder to find the words. One notable exception to this rule is found among the Jahai people, a group of hunter-gatherers living in the ...

Recommended for you

A new bound on axions

January 22, 2018

An axion is a hypothetical elementary particle whose existence was postulated in order to explain why certain subatomic reactions appear to violate basic symmetry constraints, in particular symmetry in time. The 1980 Nobel ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.