By Nicole Hess MS, CCC-SLP
Fridays Column Focus on Language by Nicole Hess.
I get this question ALL the time. In fact I just gave a talk to a group of preschool teachers and this question came up: Can teaching sign language to my baby delay his talking? Lets look at what the research tells us about using signs with babies. In an article published in the American Journal of Speech Language Pathology Elizabeth Crais, et al. provided an overview of the research on gestural communication and its effect in language development. For years, actually since I began practicing, I have used gesture development in early intervention. However, only recently has this practice been actively researched. This is in part due to the expanding research on Autism. Yet, most parents when told that the use of gestures helps verbal development fear that gestures will replace words. It seems that the research does not support that fear.
A review of: Crais, E., Watson, L., & Baranek, G. (2009). Use of Gesture Development in Profiling Childrens Prelinguistic Communication Skills American Journal of Speech-Language Pathology, 18 (1), 95-108 DOI: 10.1044/1058-0360(2008/07-0041)
The authors first provided a summary of gestures and their developmental course. There are two types of gestures: deictic and representational. Deictic gestures are either contact or distal and they are used by the child to refer, call attention to, or indicate and object or event. Contact gestures require contact between the child and adult (pushing away an adults hand for “no”) but distal gestures do not require contact (pointing or reaching). Representational gestures are semantic in nature. They can be object-related or culturally defined gestures that refer to a cultural or social action or concept (for example shushing). Deictic gestures emerge first around 7-12 months and representational gestures emerge closer to 12 months.
The authors discussed research showing that the use gestures by infants is a good indicator of later language development. Gestures can differentiate between typically developing children and those with language delays at the age of 9-12 months. And later, they can differentiate between children with different developmental delays such as Down’s Syndrome and Autism. Children with good prelinguistic gestural communication at 14 months usually have better comprehension at 24 and 42 months than those who do not. Thus, assessment of gestures can help differentiate a “late-talker” from a true language delay. Furthermore, symbolic play (which requires gestures) is not only associated with cognitive skills, but it has also been shown to predict later language skills. Gestures play a large role in symbolic play from pretending to drink to indicating night-night by closing eyes and putting hands against the head.
The authors then discussed the developmental trajectory of gestures and the number of behaviors within the use of gestures that are important. Typically 12-month-olds use one gesture per minute, 18-month-olds use two, and 24-month-olds use five gestures per minute. The type of gesture also changes with development. Twelve month-olds use mostly vocalizations or gestures, 18-month-olds begin to ad words, and 24-month-olds use mostly words. There are also specific gestures that are important markers or predictors of normative development. For example, pointing has been linked to better language development, especially receptive vocabulary. The extent to which a gesture has communicative function plays a role as well, so that the more intent is embedded in the gesture, the better the outcome for language development. Another important landmark in communication is when gestures are paired with eye gaze and vocalizations. In fact, in normative development we expect a child to move from eye gaze and vocalization to gestures and vocalization, and then to gestures and words. As you can see, just as language follows a developmental path, so do these prelinguistic sounds and motor movements.
So how do speech therapists assess gestures? Currently there are two assessment tools with specific focus on gestures; the Communication and Symbolic Behavior Scales Development Profile (CSBS-DP; Wetherby and Prizant, 2002) and the MacArthur-Bates Communicative Development Inventories, Words and Gesture Form (CDI; Fenson et al., 2002). The Rossetti Infant-Toddler Language Scale also has a strong focus on gestures but does not have normative data. Essentially though, gestures are assessed informally and are an integral part of an assessment and goal development.
Ok, so we know that the use of gestures by children is associated with better outcomes. But does this also mean that teaching gestures is associated with good outcomes? Most of the research says yes. For example, the teaching of gestures has been found to promote language development in children with autism (see for example Communication Intervention for Children with Autism: A Review of Treatment Efficacy). In addition, teaching gestures to infants has been associated with better language development in a number of studies (see for example Impact of Symbolic Gesturing on Early Language Development). And although there is still some controversy about this issue (a meta-analysis conducted by Johnston et al -DOI 10.1177/0142723705050340- concluded that the evidence for the benefits of teaching signing was inconclusive), to my knowledge there is no empirical evidence suggesting that teaching your child to sign will delay his speech.
So when a parent or teacher asks me if teaching gestures and signs in conjunction with verbal development is a good idea I say yes. One caveat though. Sign language is a language just like Spanish or English. If a parent takes teaching signs to an extreme and incorporates syntax and use the signs in lieu of speech the child may use more signs than speech. Just like when a child learns more than one language in a home. And remember, there is a time of silence before both languages emerge.
Here is a very cute video of a 12-months-old using signs: