All people have different preferred methods of learning. Some prefer to touch things (hands-on) called kinesthetic, others prefer information to be delivered verbally called auditory and others still prefer to receive information through their eyes or visually.
As we age, we learn how we learn best through trial and error. For example, I prefer to see information visually. Second to this I prefer to hear it and lastly I like to learn through touching or kinesthetic. I use words such as “I can SEE that”, “I’m trying to PICTURE what you are saying” or “I’m having problems VISUALIZING what you’re getting at.” When information is complex, I tend to want to draw things out on paper and without it, I’m totally lost.
Babies are no different. Some babies will be kinesthetic, some auditory and some visual. Baby sign language has a little bit of everything for all types of learners. The hands are manipulated, the signs are seen and the words are said out loud and so are heard. This activates many brain centers and when you aren’t sure what sort of audience you have, you’re best to use as many different channels as you can. Using so many channels has been postulated to be the reason baby sign language boosts IQ in babies and creates greater vocabularies and helps advance reading skills. It’s just that babies who learn to sign, use more of their brain than do non-signers.