New studies of "babbling" in hand gestures by deaf infants indicate that the development of language abilities in humans -- both spoken and signed language -- follows a rigid pattern dictated by the organization of the brain.
The new results indicate that both manual and vocal babbling are inherent characteristics of the growing brain as it learns the structure of language, Canadian researchers report today in the journal Science.
Linguists and psychologists have long recognized that babbling is not simply a random uttering of sounds, but the first stage in the acquisition of language abilities. As such, it follows a very precise pattern.
The Canadian scientists report that the same evolution of language appears to take place in deaf infants who are exposed to sign language.
The findings support arguments that the human brain has specific biological programming that gives humans the innate capacity for language, says linguist Lila Gleitmanof of the University of Pennsylvania.
"So, in my favorite old phrase, 'Deny it to the mouth and it will dart out through the fingers.' "
Simply put, the new results "tell us that language is distinct from speech," says psychologist Laura Ann Pettito of McGill University.