A first-of-its-kind study using the World Wide Web to collect data from more than 10,000 study subjects ages 11 to 85 found that humans' inborn "number sense" improves during school years, declines during old age and remains linked throughout the entire lifespan to academic mathematics achievement.
The study, led by psychologist Justin Halberda of The Johns Hopkins University and published during the week of June 25 in the online Early Edition of the Proceedings of the National Academy of Sciences, is groundbreaking for presenting a picture of how our basic cognitive abilities may change across our lifetime.
Psychologist Justin Halberda collected data from 10,000 subjects who played a simple game online and answered questions about their math abilities.
The term number sense is used to describe humans' and animals' inborn ability to intuitively size up the number of objects in their everyday environments. It's what enables a skittering squirrel, for example, to quickly ascertain which tree offers the most acorns, or a late-to-work motorist to figure out which E-ZPass lane will get him on his way fastest. Scientists believe we are all born with this ability. They think it probably is an evolutionary adaptation that permitted our human and animal ancestors to survive in the wild.
In the study, everyday folks visited a website to play a simple game that tested their intuitive number sense by asking them to view screens displaying varying numbers of yellow or blue dots and decide rapidly which were more plentiful. (Readers can take the test themselves at panamath.com.) The test subjects also reported in detail about how they did in math class throughout their school years, and on the math portion of the SAT.
Previous research links school math ability with number sense in teenagers, but this study demonstrates that the relationship holds fast throughout the lifespan. Halberda and his team, however, were surprised to find that number sense peaks around the age of 30, almost a decade after other cognitive abilities reach their most acute.
These results suggest that a person's number sense is not set in stone, Halberda says, and may be improved by the things we do daily, such as deciding which grocery store checkout line has the fewest shoppers or which airport security line will move most quickly.
The fact that some people seem to be born with—or to develop—more acute number sense than others also has important implications educationally. The finding that number sense is, in a way, malleable leaves open the possibility of developing educational strategies to improve people's number sense, Halberda says.
The study was funded by the National Science Foundation and the Eunice Kennedy Shriver National Institute of Child Health and Human Development.