The average scores of children in the study that were in the group that used Baby Sign Language were found to be higher than the control group who did not. By the age of twenty-four months, the signing children had a developmental advantage of three months over the non-signing children. By the time these signing children reached the age of thirty-six months, this advantage had increased dramatically from a three month developmental advantage to an equivalent twelve month advantage in their overall language skills and comprehension.
http://www.articlerich.com/.../benefits-of-baby-sign-languag...


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Note added at 1 hr (2010-01-15 14:58:09 GMT)
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These "literacy activities" are not complex, but many parents in rural and inner-city schools are lacking the fundamental principles of literacy development because they did not learn them or are not confident enough to use materials and resources that can be provided in the home and community environments. These simple activities can give their children a developmental advantage in reading, writing, and other components of language and communication before they enter kindergarten and first grade.
http://goliath.ecnext.com/.../Developing-early-reading-and-w...

Research shows that Reach Out and Read parents are up to ten times more likely to read more to their young children. Children who participate in Reach Out and Read have an approximate six-month developmental advantage in language over their peers by the time they are 2 years old.
http://www.reachoutandread.org/newsroom/press_article.aspx?i...