line.
At the urging of those parents in our research studies who suspected that there were long-term benefts, we conducted a follow-up to our National Institutes of Health study. We compared two groups of eight-year-olds, former signers and nonsigners, using the WISC-III, a traditional IQ test. The results were startling and impressive. The children who had been signers had IQ scores on the average 12 points higher than their nonsigning peers. They scored an average of 114, while the children who had never learned signs averaged 102. (The average child in the United States scores 100 on the test.) We controlled for family income, education, and other factors that infuence IQ scores. What does this mean? While the nonsigners were on average scoring just about as you would expect eight-year-olds to score, the former signers were performing
more like nine-year-olds! Why such a positive long-term effect? For one thing, we believe that the early
language advantage that signing yields serves children very well as they continue on into elementary school, helping them understand things better, explain things better, and ask better questions when they are confused. This possibility is strongly supported by independent research from Stanford University by Virginia Marchman and Anne Fernald showing that babies with better verbal language skills at twenty-fve months did signifcantly better on cognitive tests at eight years. They suggest that improvements in what researchers call working
memory (the ability to hold things in immediate memory) may be what underlies the connection.
It also seems likely that the love of books we see develop among signing babies—because they can take an active role in labeling things very early on—continues to stand them in good stead as they learn to read. Given that reading is fundamental to achievement in school, anything that supports the development of literacy is likely to also promote advanced cognitive skills.
