Since all people, babies included, learn through repetition, signing serves as a powerful educational tool. Parents who sign with their babies tend to repeat words, both verbally and with signs, more than parents who only speak to their babies. Where a non-signing parent might just ask their baby, "Do you want more?" a signing parent might sign "more" several times while verbally asking, "Do you want more? More? Okay, I'll give you more." So signing babies tend to get more exposure to each word being emphasized with a sign. Moreover, each of those words is reinforced by the multiple modalities in which it is conveyed to and from the child: audibly, visually, and kinesthetically.

During his [Dr. Joseph Garcia] research, he discovered that hearing children began replicating signs as early as eight months, with some exceptional children as early as six months. This new discovery seriously challenged the opinion of many child development experts, including Piaget who theorized that babies can't mentally represent symbols until they are almost two, and therefore can't learn to talk until then.

Joseph also found that once the signing children began speaking, they tended to have a better grasp of grammar and syntax, past and present tenses, and of language in general.

One might think that if an emphasis is placed on manual communication, verbal communication will be delayed. In fact, the reverse seems to be true. When this issue was reviewed in Acredolo and Goodwyn's study, it was discovered that not only do signing children tend to learn to speak sooner, but by age two they have a vocabulary of 50 more real words, on average, than their non-signing counterparts.

By age three, children exposed to signing had language skills approaching that expected of four year olds. In the same way that crawling seems to stimulate a child's interest in walking, signing seems to provide an excellent bridge to verbal communication.