Tuesday, May 13, 2014

Baby Sign Language/Gesturing and Language Development

A few weeks ago, we asked readers to send us their questions about infant communication. We received some great questions and wanted to get started by answering this one:

Any evidence of using signs increasing or decreasing language development?

As researchers and mothers, we’ve heard a lot about baby signing over the years and like this reader, we’ve wondered, what does the evidence say? While baby signing has become very popular, does scientific research support its use?
The benefits of baby sign language can be a pretty controversial topic. There are many parental reports of great benefits for infants taught baby signs, such as decreased frustration and tantrums, early verbal skills, and improved infant-parent interaction and bonding, just to name a few. However, the scientific research is not as promising. The majority of studies have been small and researchers have been unable to confirm that infant signing benefits babies' language development. Limited research does suggest that babies can learn and use sign language to help them communicate prior to using spoken words, but whether or not this improves their language development is questionable. On the other hand, there is also no research that shows that signing hinders language development. There is also limited evidence showing that baby sign language improves mother-infant interactions. Here is an overview of a few of the recent studies that are out there.

Babies first use gestures (like pointing or reaching) around 10 months of age. By the end of the first year they also use symbolic gestures like pretending to drink from a cup. A study by Kirk, et al (2013) sought to find out if encouraging the early use of these gestures or baby sign language specifically, impacted language development and infant-mother interactions. In this small, well-designed study, gesture training (signs) did not significantly improve language development. There was, however, some effect for males that scored low for expressive communication  (communicating with others either verbally or with gestures) at the beginning of the study; they experienced gains in their expressive communication abilities when exposed to gestures compared to those that were not (though this analysis was only done with 3 infants so it must be interpreted with caution). So what does this mean? These results may indicate that using gesturing or sign in infants who have weak language ability (defined by a lower score on a language assessment)  may improve language development later on.
The second part of this study looked more closely at the interactions between mothers and infants to see if early gesturing or signing improved how mothers related to their babies and understood their behavior. When mothers relate well to their babies and understand their behavior, they have a more secure infant-caregiver attachment and later ability to understand others’ thoughts and feelings. While the study found no significant difference in maternal-infant relatedness between gesture/signing groups and those who did not learn them, there were small positive changes in the mothers’ responsiveness to their infants’ needs and non-verbal cues.

A small study by Gongora & Farkus (2009) showed some improvements in mother-infant interactions, with higher frequencies of visual, tactile (touch) , and vocal mother-infant interactions, when mother-infant pairs were exposed to an infant sign language program.
Vallotten (2012) examined the effects of using signs with infants in a group childcare setting on caregiver responsiveness. The authors found that, at 10 months of age, infants’ use of responsive gestures with their caregivers positively influenced the quality of care they received. They also found that at 15 months the frequency of infant signing slowed, possibly because the infants were speaking more, while variety of signs used increased rapidly. Interestingly, caregivers responded less often as signing variety increased. As variety of signs became more common, their impact on caregiver behavior slowed.

Just as understanding and responding to infant cues can improve infant-caregiver interactions and lead to less parental stress, signing and gesturing may have a similar effect after 8-10 months of age when babies begin gesturing. Studies show that babies can learn and use signs to communicate with their caregivers, and this may improve communication and lessen frustration for both the parent and baby until the baby can talk. However, there is currently not enough scientific evidence to show that baby signing enhances language development or gives babies advanced learning capabilities compared to infants that don’t sign.  Practicing baby sign language can be a great opportunity for parents and infants to bond and interact together. I used a few signs when my daughter was a baby, especially around mealtime, and it added to my understanding of her hunger and fullness cues. Using baby signs has not been shown to be detrimental to infant language development. Research does show that verbally labelling objects can help language comprehension, so while signing be sure to say the word out loud as well. What has been your experience using infant sign language?

References
Kirk E, Howlett N, Pine KJ, Fletcher BC. To sign or not to sign? The impact of encouraging infants to gesture on infant language and maternal mind-mindedness. Child Dev. 2013;84(2):574-90.
Gongora X, Farkas C. Infant sign language program effects on synchronic mother-infant interactions. Infant Behav Dev. 2009;32(2):216-25.

Vallotten. Do infants influence their quality of care? Infants’ communicative gestures predict caregivers’ responsiveness. Infant Behav Dev. 2009;32:351-365.

2 comments:

  1. I find signing to be extremely helpful both on its own and as a disambiguation between similar words. For instance, hippo and apple sounded exactly the same when my daughter said them, but the signs looked very different. Now I'm finding with my son that his verbal development is a little slower, and I sometimes can't identify the sign he's using. I wonder if the decreased understanding from caregivers as the variety of signs increases is partially due to lack of shared vocabulary between caretakers-e.g. my son and I both know the sign for boat, but I had to teach it to his sitter.

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  2. I wonder whether decreased advantages with variety of signs has to do with decreased understanding on the part of caregivers? I know with my son, whose words are still reasonably unarticulated at 21 months, he often signs something that could be, for instance, TRAIN or SHEEP or GENTLE or SIT or CATERPILLAR, and I need context (and of course to know the sign in the first place!) to identify what he's actually trying to say.

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