Sorry. That was possibly the weakest pun in the history of MN and I still couldn't resist it.
The paper is [[http://jn.physiology.org/cgi/content/full/77/5/2704 here].
It's not about weaning: the authors were analysing chewing in 1-4 year olds. However, their area of expertise also includes speech development, and towards the end of the discussion section there's this paragraph:
Potential role of mastication in the development of speech
"... no evidence exists to suggest that the coordinative patterns of chewing necessarily precede those essential to speech production. In fact, Moore et al. (1988) have demonstrated in adults that the coordinative strategies for mandibular control during speech are quite different from those employed during chewing. Similarly, toddlers have failed to exhibit gross similarities in speech and mastication (Moore and Ruark 1996). The present findings extend previous comparisons, revealing that the coordinative organization for chewing did not exhibit characteristics similar to those observed for speech production, either by adults or children."
In English: Chewing and speech are not the same and one does not develop from the other.
So if a child's starting on solids later than the norm they're not necessarily condemmned to a life of letter-writing and charades.