The concept of number lines, a hallmark of elementary math classrooms, does not reflect universal human intuition, and instead appears to be learned, based on a study of an indigenous group in Papua New Guinea. The full results are published Apr. 25 in the open access journal PLoS ONE.
Rafael Núñez of University of California, San Diego led the research team, which found that unschooled adults from a remote group in Papua New Guinea mapped numbers onto space, but when placing numbers on a line, they only used the endpoints—a categorical response, rather than intermediate points on the line. In contrast, individuals from the same ethnic group who had received formal education used the entire number line, not just the endpoints, showing that this more nuanced metric-driven understanding of the line can be learned and enforced by education and cultural practices.
Source: Public Library of Science