Children are able to gesture long before they have the physical skills to speak. So, if you teach them some basic signs, they'll be able to communicate their needs months before they'd be able to speak them. As for whether it helps learning in general, I don't know.
Dr. Marilyn Daniels at Penn State University has found that hearing students in pre-kindergarten classes who receive instruction in both English and ASL score significantly higher on the Peabody Picture Vocabulary Test than hearing students in classes with no sign instruction. Her studies demonstrate that adding visual and kinesthetic elements to verbal communication helps enhance a preschool child's vocabulary, spelling and reading skills.
The most recent meta-study (as far as I know) has this to say...
Doherty-Sneddon concludes by arguing there are three different levels of support for the benefits of baby signing: indicative, if not evidentially strong, evidence from baby signing research; related evidence from deaf sign and hearing gesture/language research; compelling anecdotal support from families who have embraced the approach.
Daniels, M. (1996). Seeing language: The effect over time of sign language on vocabulary development in early childhood education. Child Study Journal, 26, 193-208.
Daniels, M. (October, 1994). The effects of sign language on hearing children's language development. Communication Education, 43, 291-298.
Daniels, M. (1996). Seeing language: The effect over time of sign language on vocabulary development in early childhood education. Child Study Journal, 26, 193-208.
Other researchers have found evidence that sign language supports early literacy skills.
Felzer, L. (1998). A Multisensory Reading Program That Really Works. Teaching and Change, 5, 169-183.
Wilson, R., Teague, J., and Teague, M. (1985). The Use of Signing and Fingerspelling to Improve Spelling Performance with Hearing Children. Reading Psychology, 4, 267-273.
Hafer, J. (1986). Signing For Reading Success. Washington D.C.: Clerc Books, Gallaudet University Press.
Koehler, L., and Loyd, L. (September 1986). Using Fingerspelling/Manual Signs to Facilitate Reading and Spelling. Biennial Conference of the International Society for Augmentative and Alternative Communication. (4'th Cardiff Wales).
Dr. Marilyn Daniels at Penn State University has found that hearing students in pre-kindergarten classes who receive instruction in both English and ASL score significantly higher on the Peabody Picture Vocabulary Test than hearing students in classes with no sign instruction.
Thanks for providing these articles. I don't doubt that children can learn to sign before they can learn to speak (not a big leap considering that babies can understand language before they can move their vocal muscles well enough to produce it), or that they'd be happier being able to communicate earlier.
What I do doubt is that this has any long-term effects on their development, above and beyond the effect of learning more than one language. In any of the longitudinal studies, do they control by having a second group of infants learn two spoken languages?
Anecdotal, I know, but the smartest guy I know (13 courses one semester at Waterloo, qualified to major in CS, actuary science, accountancy, pure math with minors in psychology and business. Currently working on his law degree, actuary tests, and CFA (certified financial advisor) while working full time as a chartered accountant) was taught baby sign as an infant. His younger brother was not. His younger brother is so much more creative and broad thinking whereas the eldest is a Spock like linear thinker. Trade offs.