Counting

Some time ago I have learned about the Amazonian tribe of Piraha, who, apparently have very, very simple system of mathematics. (as described by Rochel Gelman and Brian Butterworth ):
"The Munduruku language uses the count words for 1, 2 and 3 consistently, and 4 and 5 somewhat inconsistently. The Piraha do not even use the words for 1 and 2 consistently. How would members of these groups perform on various non-verbal tasks involving numerosity?
The amazing result was that both groups succeeded on non-verbal number tasks that used displays representing values (in one study) as large as 80."


I recall the Piraha story because of totally unrelated paper by
Irene M. Pepperberg called Grey parrot numerical competence: a review .
The abstract of the paper states:

"The extent to which humans and nonhumans share numerical competency is a matter of debate. Some researchers argue that nonhumans, lacking human language, possess only a simple understanding of small quantities, generally less than four. Animals that have, however, received some training in human communication systems might demonstrate abilities intermediate between those of untrained nonhumans and humans. Here I review data for a Grey parrot (Psittacus erithacus) that has been shown to quantify sets of up to and including six items (including heterogeneous subsets) using vocal English labels, to comprehend these labels fully, and to have a zero-like concept. Recent research demonstrates that he can also sum small quantities. His success shows that he understands number symbols as abstract representations of real-world collections, and that his sense of number compares favorably to that of chimpanzees and young human children."

Does make you think, doesn't it?