Study finds twist to the story of the number line: number line is learned, not innate human intuition
Baku, April 27 (AzerTAc). The study, published in April 25, is based on experiments with an indigenous group in Papua New Guinea. It was led by Rafael Nunez, director of the Embodied Cognition Lab and associate professor of cognitive science in the UC San Diego Division of Social Sciences.
"Influential scholars have advanced the thesis that many of the building blocks of mathematics are `hard-wired` in the human mind through millions of years of evolution. And a number of different sources of evidence do suggest that humans naturally associate numbers with space," said Nunez, coauthor of "Where Mathematics Comes From" and co-director of the newly established Fields Cognitive Science Network at the Fields Institute for Research in Mathematical Sciences.
"Our study shows, for the first time, that the number-line concept is not a `universal intuition` but a particular cultural tool that requires training and education to master," Nunez said. "Also, we document that precise number concepts can exist independently of linear or other metric-driven spatial representations."
The upper Yupno valley, like much of Papua New Guinea, has no roads. The research team flew in on a four-seat plane and hiked in the rest of the way, armed with solar-powered equipment, since the valley has no electricity.
The indigenous Yupno in this area number some 5,000, spread over many small villages. They are subsistence farmers. Most have little formal schooling, if any at all. While there is no native writing system, there is a native counting system, with precise number concepts and specific words for numbers greater than 20. But there doesn`t seem to be any evidence of measurement of any sort, Nunez said, "not with numbers, or feet or elbows."
In their time study with the Yupno, now in press at the journal Cognition, Nunez and colleagues find that the Yupno don`t use their bodies as reference points for time -- but rather their valley`s slope and terrain. Analysis of their gestures suggests they co-locate the present with themselves, as do all previously studied groups. (Picture for a moment how you probably point down at the ground when you talk about "now.") But, regardless of which way they are facing at the moment, the Yupno point uphill when talking about the future and downhill when talking about the past.