An open question about the nature of human intelligence is the degree to which language is linked to other cognitive functions. Numerous claims have been made, for example, that the ability to do mathematics should be linked to the ability to handle grammar, and indeed such an idea does seem quite natural. Now, however, it looks as though this idea must be discarded.
Rosemary Varley and colleagues at the University of Sheffield studied three men with brain damage, which affected their ability to handle grammar. To the surprise of the researchers, the men retained full ability to do computations, including recursion, and also to deal with structure-dependent concepts such as expressions with brackets. This is the first time it has been shown that if mathematics is a language, it is certainly not like language as we know it from linguistics.
Further reading
Rosemary A Varley et al. 2005 Proc. Nat. Acad. Sci. 102 3519.