Victor Mair has an extremely interesting post up at the Log:
[...]I’ve long been intrigued by the fact that the number of basic morphemes in Sinitic is roughly comparable to the number of roots in Proto-Indo-European (PIE). I wondered whether this was purely a coincidence or a reflection of some fundamental feature of language and the human brain. So I started to look at other language families to see whether they too had a similar amount of root morphemes.
As I gathered and examined data, they seemed to confirm my initial impression that the essential etyma of many languages amount to approximately 1,000-2,000, with most falling at around 1,200-1,500. Wanting to secure more precise and reliable evidence, I asked colleagues who are specialists in various fields to share their expertise.
He quotes John Huehnergard on Semitic, Philip Jones on Sumerian, Michael Witzel on Nostratic and PIE, Allan Bomhard on Nostratic, John Colarusso on Caucasian languages, and Don Ringe, J. P. Mallory, and Douglas Adams on PIE, all very interesting, and himself discusses Sinitic, concluding:
[...]I think that the fact that the quantity of basic building blocks of various languages is roughly comparable is not merely coincidental, but may have something to do with the cognitive makeup of the brain. That is to say, at the bottom limit, for a language to become an organic, functioning entity, it needs to have a sufficient amount of constituent, core etyma from which a working vocabulary may be derived. At the other end of the scale, there seems to be an upper limit to the number of primary conceptual categories that the mind is capable of processing.
It seems that, in general, there are roughly 1,200-1,500 root concepts from which all others are generated. This appears to hold for many language families. Inventories of core etyma with a magnitude that are much over 2,000 or much under 1,000 are probably the result of differing definitions of what constitutes a basic root and how the computations are carried out.
Fascinating stuff, and I look forward to the ensuing discussion!