PNAS – Proceedings of the National Academy of Sciences of the United States
of America
(Accessed 8 November 2014)
http://www.pnas.org/content/early/

Probabilistic cognition in two indigenous Mayan groups
Laura Fontanaria, Michel Gonzalezb, Giorgio Vallortigarac, and Vittorio Girottoa,1
Author Affiliations
Edited by Philip N. Johnson-Laird, Emeritus Princeton University, Princeton, NJ, and approved October 3, 2014 (received for review June 6, 2014)
Significance
Correct probabilistic evaluations are one of the hallmarks of rationality. Is the human ability to make them dependent on formal education, or does it emerge regardless of instruction and culture? This paper shows that preliterate and prenumerate Mayan adults are able to solve a variety of probabilistic problems. These individuals correctly use prior and posterior information, proportions and elementary combinatorial procedures to predict the occurrence of random outcomes. And they perform like Mayan school children and Western controls. The finding that adults with no formal education are able to make suitable predictions indicates that, regardless of schooling and culture, the human mind possesses a basic probabilistic knowledge.
Abstract
Is there a sense of chance shared by all individuals, regardless of their schooling or culture? To test whether the ability to make correct probabilistic evaluations depends on educational and cultural guidance, we investigated probabilistic cognition in preliterate and prenumerate Kaqchikel and K’iche’, two indigenous Mayan groups, living in remote areas of Guatemala. Although the tested individuals had no formal education, they performed correctly in tasks in which they had to consider prior and posterior information, proportions and combinations of possibilities. Their performance was indistinguishable from that of Mayan school children and Western controls. Our results provide evidence for the universal nature of probabilistic cognition