@Teacherofthedeaf
Continued.,...
Here's a few points with the associated research from another site:
*CHILDREN WHO LEARN SIGN LANGUAGE MAY HAVE MORE BRAIN CAPACITY LATER, LEARN TO SPEAK SOONER, AND DO BETTER ON FUTURE IQ TESTS. (THE DAILY OKLAHOMAN, MARCH 1999)
*11-MONTH-OLDS WHO LEARNED...