• Tag Archives human brain
  • New study finds that numbers are inherent to humans…and…

    I came across this study today from The New Yorker.

    It’s a long (for the internet) read, so I’ll only do a few verbatim copies here. The gist of the study, by French scientist Stanislas Dehaene, is that the concept of integers (1,2,3 etc) is something that is hard wired in our brains. We have a natural ability to do rudimentary addition, and we can tell when one number is larger than another. Well, as long as the gap is large enough.

    According to the article:

    If you are asked to choose which of a pair of Arabic numerals?4 and 7, say?stands for the bigger number, you respond ?seven? in a split second, and one might think that any two digits could be compared in the same very brief period of time. Yet in Dehaene?s experiments, while subjects answered quickly and accurately when the digits were far apart, like 2 and 9, they slowed down when the digits were closer together, like 5 and 6. Performance also got worse as the digits grew larger: 2 and 3 were much easier to compare than 7 and 8. When Dehaene tested some of the best mathematics students at the ?cole Normale, the students were amazed to find themselves slowing down and making errors when asked whether 8 or 9 was the larger number.

    Dehaene conjectured that, when we see numerals or hear number words, our brains automatically map them onto a number line that grows increasingly fuzzy above 3 or 4. He found that no amount of training can change this. ?It is a basic structural property of how our brains represent number, not just a lack of facility,? he told me.

    This is fascinating. Especially the discovery of a “hard wired” number line (which goes right to left, apparently. See the article), which works really well up to about 4. The fascination comes not from the discovery of this in humans, but the fact that this degree of rudimentary math has been found in a wide variety of animals. The most recent being fish.

    In that study, scientist found mosquito fish (Gambusia affinis) females were able to count up to four (right at the end of the number line). Also, like in human studies, the fish were able to tell which group of fish was larger, as long as the discrepancy was big enough (approximately 2:1).

    Keeping with the theme of my site, the most famous example of reptilian counting would be that of varanids. Studies on the white throated monitor (Varanus albigularis), found that they can reliably count to six (King & Greene, 1999).

    So it seems that the concept of math is so important that it has been hard wired in our genes for at least 400 million years.

    Think about that the next time you ignore a mathematical equation.

    Also, give the article a read through. It is very intriguing. It’s the closest that psychology has ever come to being a hard science, and the ramifications for education cannot be understated.

    ~Jura



    King, D. & Green, B. 1999. Goannas: The Biology of Varanid Lizards. University of New South Wales Press. ISBN 0-86840-456-X, p. 43.