why

The language of the Piraha, an Amazonian tribe of around 200 hunter-gatherers, does not include any words for numbers (in fact, they lack words for many things), and despite intense instruction, no one has been able to teach the adult Piraha to count. This has been interpreted by some as evidence that language profoundly constrains thought - a strong version of the Whorfian hypothesis.However, there is a theoretical divide in the study of the Piraha. Peter Gordon, author of a great article about the Piraha in Science, believes that the Piraha have numbers for "one" and "two," but not for any numbers greater than that. However, Daniel Everett - who spent seven years with the Piraha - suggests these words actually refer to "very small" and "small," or other very relative indications of size.The rift goes deeper than that, however. According to a recent interview in Scientific American Mind, Gordon and Everett disagree on the fundamental question ofthe Piraha have no (or very few) number words. Whereas Gordon suggests the Piraha may be "cognitively incapable" of counting, Everett believes that the Piraha have a kind of moral objection to the idea of counting.In the interview, Everett musters several pieces of evidence to support this view. First, Piraha children can learn to count culturally-relevant items - beads - which shows that the Piraha as a whole are not cognitively incapable of counting (although it's also possible that the cognitive capacity for counting is transient unless reinforced by language).Second, there are several indications that the Piraha may simply lack the desire to count. For example, Piraha refuse to learn the national language of Brazil. Everett notes that a young boy who did learn to count was actually shunned by other tribe members.Finally, other cultural facts about the Piraha that are non-specific to counting suggest a radically different view of their situation. The tribe does not have currency, has no art, and no more than 10 consonants or vowels. Everett also notes in the SciAm:Mind interview that Piraha "grammar" does not have embedded clauses - thought by some to be a defining feature of human communication systems. Although this is politically incorrect, it's clearly possible that the Piraha are severely inbred, and may manifest cognitive deficits as a result (although Dan Everett has said that "Pirahã women occasionally have children with Brazilian traders passing through, children raised as Pirahãs. These children don't show any difference I can see from other Pirahãs on these cognitive skills or language facts. I don't think genes, retardation, or other such suggestions are useful or appropriate here.")But as long as mental retardation is a possibility, it seems premature to make conclusions about the innateness of number based on Piraha behavior and language.EDIT: Predictably, I've taken heat for suggesting that the Piraha may be inbred. One person suggested that the critical number of individuals required for avoiding "inbreeding depression" is 12, which if true would suggest that the Piraha have more than enough individuals to not suffer from the bad effects of inbreeding. On the other hand, I have not been able to verify this number in any published article, and I find it hard to imagine how this number could be empirically verified in the first place. Furthermore it seems that any such number would have to be relative both to a certain number of generations of inbreeding, and to the initial genetic diversity of those 12 individuals, neither of which is known in the case of the Piraha.Related Posts: Piraha links (Language Log)