Even Everett Says: If you go back to the Pirahã language, and you look at the stories that they tell, you do find recursion. You find that ideas are built inside of other ideas, and one part of the story is subordinate to another part of the story. That's not part of the grammar per se, that's part of the way that they tell their stories. (http://www.edge.org/3rd_culture/everett07/everett07_index.ht...)
As the Harvard people argue, Everett kind-of redefined Piraha Grammar. So there isn't recursion in Everett's official grammar even through the Piraha use recursion in their communication by everyone admission.
"If you go back to the Pirahã language, and you look at the stories that they tell, you do find recursion. You find that ideas are built inside of other ideas, and one part of the story is subordinate to another part of the story. That's not part of the grammar per se, that's part of the way that they tell their stories. So my idea is that recursion is absolutely essential to the human brain, and it's a part of the fact that humans have larger brains than other species. In fact, one of the papers at the recursion conference was on recursion in other species, and it talked about how when deer look for food in the forest, they often use recursive strategies to map their way across the forest and back, and take little side paths that can be analyzed as recursive paths. So it's not clear, first of all that recursion is unique to humans, and it's certainly not clear that recursion is part of language as opposed to part of the brain's general processing.
He says Piraha doesn't have recursion and that he thinks recursion isn't essential to human languages (thus in contradiction with Chomsky theories), but that it's part of how the brain processes information.
I took note of the whole passage. Everett defines the Piraha grammar as not having recursion. He claims that when the Piraha use recursion in their linguistic communication ("story telling") they are somehow doing it outside the Piraha language. But the Piraha language is defined by the usage of the Piraha, not by one or another codified grammars.
Nevins et al. (linked above) note that recursion takes multiple forms in multiple languages and there isn't even anything terribly unusual about the form it takes in Piraha, even if this is a form Everett cannot accept into the grammar.
Even Everett Says: If you go back to the Pirahã language, and you look at the stories that they tell, you do find recursion. You find that ideas are built inside of other ideas, and one part of the story is subordinate to another part of the story. That's not part of the grammar per se, that's part of the way that they tell their stories. (http://www.edge.org/3rd_culture/everett07/everett07_index.ht...)
As the Harvard people argue, Everett kind-of redefined Piraha Grammar. So there isn't recursion in Everett's official grammar even through the Piraha use recursion in their communication by everyone admission.