Shared system for ordering small and large numbers in monkeys and humans.


Journal Article

There is increasing evidence that animals share with adult humans and perhaps human infants a system for representing objective number as psychological magnitudes that are an analogue of the quantities they represent. Here we show that rhesus monkeys can extend a numerical rule learned with the values 1 through 9 to the values 10, 15, 20, and 30, which suggests that there is no upper limit on a monkey's numerical capacity. Instead, throughout the numerical range tested, both accuracy and latency in ordering two numerical values were systematically controlled by the ratio of the values compared. In a second experiment, we directly compared humans' and monkeys' performance in the same ordinal comparison task. The qualitative and quantitative similarity in their performance provides the strongest evidence to date of a single nonverbal, evolutionarily primitive mechanism for representing and comparing numerical values.

Full Text

Cited Authors

  • Cantlon, JF; Brannon, EM

Published Date

  • May 2006

Published In

Volume / Issue

  • 17 / 5

Start / End Page

  • 401 - 406

PubMed ID

  • 16683927

Pubmed Central ID

  • 16683927

Electronic International Standard Serial Number (EISSN)

  • 1467-9280

International Standard Serial Number (ISSN)

  • 0956-7976

Digital Object Identifier (DOI)

  • 10.1111/j.1467-9280.2006.01719.x


  • eng