Scientists say we are all born with a knack for mathematics. Every time we scan the cafeteria for a table that will fit all of our friends, we're exercising the ancient estimation center in our brain.
Stanislas Dehaene was the first researcher to show that this part of the brain exists. In 1989, he met Mr. N who had suffered a serious brain injury. Mr. N couldn't recognize the number 5, or add 2 and 2. But he still knew that there are “about 50 minutes” in an hour. Dehaene drew an important conclusion from his case: there must be two separate mathematical areas in our brains. One area is responsible for the math we learn in school, and the other judges approximate amounts.
So what does the brain's estimation center do for us? Harvard University researcher Elizabeth Spelke has spent a lot of time posing math problems to preschoolers. When he asks 5-year-olds to solve a problem like 21+30, they can't do it. But he has also asked them questions such as, “Sarah has 21 candles and gets 30 more. John has 34 candles. Who has more candles?” It turns out preschoolers are great at solving questions like that. Before they've learned how to do math with numerals and symbols, their brains' approximation centers are already hard at work.
After we learn symbolic math, do we still have any use for our inborn math sense? Justin Halberda at Johns Hopkins University gave us an answer in his study. He challenged a group of 14-year-olds with an approximation test: The kids stared at a computer screen and saw groups of yellow and blue dots flash by, too quickly to count. Then they had to say whether there had been more blue dots or yellow dots. The researchers found that most were able to answer correctly when there were 25 yellow dots and 10 blue ones. When the groups were closer in size, 11 yellow dots and 10 blue ones, fewer kids answered correctly.
The big surprise in this study came when the researcher compared the kids' approximation test scores to their scores on standardized math tests. He found that kids who did better on the flashing dot test had better standardized test scores, and vice versa (反之亦然). It seems that, far from being irrelevant, your math sense might predict your ability at formal math.
