Baby Sign Language: Does It Work?

What if babies could tell us what they want, before they start crying for it? Bring in baby signing, a system of symbolic hand gestures for key works such as “milk,” “hot” and “all gone” that are taught to hearing babies as a way to communicate before they can talk. The sign for milk, for example, is made by opening and closing the hand, while the sign for “more” by tapping the ends of the fingers together. Now new research has reported that it’s even possible for babies to learn these signs just from viewing videos at home. The study found that babies learned to produce baby signs just as well from a video as they did if they were taught by their parents. Yet only those babies who had been taught the signs from a parent showed evidence of understanding what the signs meant. The bigger question is whether these findings should be taken as encouragement to teach babies to sign and what impact it has on child development.

Should parents be encouraged to sign with their babies? This is a question that I’m often asked and it’s one I’ve tackled in my own research. Baby signing burst onto the booming baby market back in the 1990s and has since gone global, attracting parents to spend money on classes, books and DVDs with claims that Baby Sign can help “improve” their baby in some way. Accelerated speech development, reduced frustration and increased IQ are just some of the claims that have been made. But there is little evidence to support these claims. In 2012, American researcher Lauri Nelson and colleagues published an analysis of the credibility of the claims made on baby sign websites. Across the 33 baby sign websites they identified, there was a high level of consistency in the types of claims made. Nelson traced the source of the evidence for each claim and found that more than 90 percent were based on opinion articles, not science. None of the claims relating to reduced tantrums, better self-esteem, or improved parent-child bonding were supported by any evidence at all, opinion or empirical.

So what about the evidence for the other 10 percent? A review paper published in 2005 examined evidence from 17 studies published between 1980 and 2002 that had evaluated the effectiveness of signing with infants who could hear. It concluded that the existing research was methodologically flawed and, because of this, there was “no evidence to suggest that Baby Sign had any benefits for child development.” This prompted me to conduct my own experiment, avoiding the pitfalls of previous studies, to test whether baby sign improves language development. I randomly allocated parents and their babies to either baby sign training or a control condition and routinely measured the babies’ language development over one year, from when babies were eight months up until 20 months. While the babies learned and used the signs (often before they could speak), doing so made no significant impact on their language development. The babies who signed did not start to talk any earlier, nor did their language progress any quicker than the babies in the control conditions. Others have subsequently replicated this finding and another review paper published in December 2014 concluded that “there is no strong evidence to support the claimed benefits of baby sign.”

While the evidence clearly fails to support the notion that baby signing boosts development, there is no evidence that is actually harms or hinders child development. No studies have reported any negative effect of learning baby sign language on children’s outcomes. However, other research I have been involved in found that parents who chose to attend a baby signing class had significantly higher stress levels than parents who attended other, non-educational classes with their baby. Our interpretation of this finding was that parents with higher pre-existing stress may have been attracted to Baby Sign classes because of types of claims made about how baby sign can benefit them and their baby. This is not to say that baby signing can’t be a fun thing to do: many parents and their children gain great pleasure from learning and using it together. But we need to move away from the fiction and stick to the facts: there is no evidence to support the claim that baby signing will accelerate a child’s development.

This article was originally published on The Conversation.

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