Comment on

• Numerical cognition without words: evidence from Amazonia.

  Gordon P. Gordon P. Science. 2004 Oct 15;306(5695):496-9. doi: 10.1126/science.1094492. Epub 2004 Aug 19. Science. 2004. PMID: 15319490
• Language and the origin of numerical concepts.

  Gelman R, Gallistel CR. Gelman R, et al. Science. 2004 Oct 15;306(5695):441-3. doi: 10.1126/science.1105144. Science. 2004. PMID: 15486289
• Exact and approximate arithmetic in an Amazonian indigene group.

  Pica P, Lemer C, Izard V, Dehaene S. Pica P, et al. Science. 2004 Oct 15;306(5695):499-503. doi: 10.1126/science.1102085. Science. 2004. PMID: 15486303