Baby sign language: A guide for the science-minded
© 2009 - 2012 Gwen Dewar, Ph.D., all rights reserved
Does baby sign language work?
Your 10-month old baby is crying. You ask him what he wants.
He lifts his hand in the air and squeezes his fingers shut—your family’s sign for milk.
Is this sort of communication really possible?
Research suggests that it is. In this article, I review the scientific basis for baby sign language. I address these questions:
• What is it?
• Why should parents use it?
• When can parents start?
• What’s the best way to begin?
As I note below, some studies suggest that babies whose parents communicate with a combination of speech and gesture may develop larger spoken vocabularies, and that's been a key selling point for many commercial baby signing programs. But the most recent research doesn't support the idea that teaching signs to babies makes them learn more words.
What seems more likely is that gestures can improve communication and make parents more savvy or sensitive to what their babies are thinking about. And that's no small thing. When parents are more tuned into their baby's thoughts and feelings, babies are more likely to develop secure attachment relationships. They may also provide their babies with more opportunities to explore and learn.
But let’s start at the beginning. What do people mean when they say they are teaching their babies to sign?
Defining baby sign language: What is it?
It’s probably misleading to call it baby sign language. That implies that babies are learning a full-blown language, like American Sign Language (ASL).
Of course, you can teach your baby ASL if you want--just as you can teach your baby any other second language. Babies who are raised in bilingual environments take longer to master their first language. But they eventually catch up and enjoy the advantage of being fluent in more than one language.
But when people speak of research that supports the use of “baby sign language,” they are usually referring to something else. They are talking about encouraging babies to communicate with their hands. This includes
• Pointing at things of interest, and responding appropriately when babies point. (Example: When baby points at a cat, you say “That’s a cat!”)
• Actively teaching symbolic gestures--gestures that “stand for” something else (Example: To represent the concept of “food” or “eating,” you hold your fingers together, as if grasping something, and bring them to your lips)
• Responding to symbolic gestures that babies might invent (Example: Baby tugs at her shirt while she makes a questioning sound, meaning “Could you help me take off my shirt?”)
This isn’t real sign language. Real sign language has grammatical rules and a whole lexicon of abstract signs--symbolic gestures that bear no obvious connection to the things they stand for.
By contrast, baby signs are more transparent. It’s easier to guess what baby signs mean. And maybe that’s why baby sign language is helpful. As we'll see below, signs that aren't iconic or representational -- gestures that have no obvious connection with their referents -- might make it harder for babies to learn.
But is "baby sign language" helpful? Let’s consider the facts.
Do "baby signs" improve communication between parents and babies?
Even if you don't train your baby to use symbolic gestures, it's likely he'll discover one on his own: The act of pointing.
Most babies begin pointing between 9 and 12 months, and this can mark a major breakthrough in communication. The baby learns that she can make her wishes known by making eye contact and then shifting the direction of your gaze.
By pointing, babies can make requests (i.e., “Give me that toy.”) They can also ask questions (“What is that?”) and make comments (“Look at that!”)The breakthrough gives parents insights into what their babies are thinking, and that’s a good thing.
As psychologists Jana Iverson and Susan Goldin-Meadow have noted, babies who gesture frequently might get better language feedback from their parents (Iverson and Goldin-Meadow 2005). A baby who points at a new object might prompt his mother to label and discuss the new object. So the baby gets the information at just the right moment—when she is curious and attentive.
It’s also possible that baby sign language motivates parents to speak more emphatically, with greater variations in pitch, and with greater emotion. Research suggests that this sing-song style of speaking--called
--helps babies learn to talk.
And one of the most important perks of baby sign language may be social.
In a recent study, Elizabeth Kirk and her colleagues (2012) randomly assigned 20 mothers to supplement their speech with symbolic gestures of baby sign language. The babies were tracked from 8 months to 20 months of age, and showed no linguistic benefits compared to babies in a control group.
But the mothers who had been instructed to use gestures behaved differently. They were responsive to their babies' nonverbal cues, and they were more likely to encourage independent exploration.
Such results suggest that attempts to use baby signs may make parents more mind-minded --
an approach that is linked with more secure attachment relationships.
But what about the bigger question? If you teach your baby symbolic gestures, will she develop any lasting verbal advantage?
Do "baby sign" programs have a lasting impact on your child's vocabularly?
There is strong evidence that
older children become better learners and problem solvers when they gesture,
and some research suggests that early gesture use is linked with vocabulary development.
For instance, Meredith Rowe and her colleagues tracked a group of American babies from the age of 14 months. They found that the more a baby used gestures at 14 months, the bigger his spoken vocabulary was at 36 months (Rowe et al 2008). This relationship held even after adjusting for socioeconomic status and other background variables.
But the correlation between baby signs and spoken vocabulary might reflect general language ability. Babies who use more gestures might be more linguistically-inclined to begin with. As a result, they communicate better overall--whether by using baby sign language or spoken language.
Experiments can help clear this up. The most well-known were conducted by Linda Acredolo and Susan Goodwyn, who reported that babies developed larger receptive vocabularies when their parents were instructed to enrich their speech with symbolic gesture (Acredolo and Goodwyn 1988; Goodwyn et al 2000).
However, it’s not clear if these experiments were randomized, and I as note above, other, subsequent studies have failed to demonstrate any vocabulary advantage (Kirk et al 2012; Johnston et al 2005).
It's even possible that certain types of gestures interfere with vocabulary learning in babies. A recent study reports that 15-month-old toddlers were less likely to learn the name for an object when the spoken word was paired with an arbitrary (non-representational) gesture (Puccini and Liszkowski 2012).
What about IQ?
Although there have been claims that baby sign language is associated with higher IQs, the relevant research has yet to appear in any peer-reviewed scientific journal. So it’s safe to say that the jury is still out.
When can I start?
Most people begin after 6 months. But some babies might benefit from learning baby sign language even before that.
Consider what we know about the timing of language acquisition.
Typical progress for spoken language acquisition
Between 7 and 10 months, most typically-developing babies begin syllabic babbling—repeating specific speech sounds, like “ba ba ba” or “ma ma ma” that are regularly used in their native language. Babies vary greatly in the timing of their first words. The average may be around 12 months. But some utter their first words well before that time, and others may take months longer (Oller 2000).
Typical progress for sign language acquisition
Babies born to deaf parents are exposed to real sign language from the very beginning. So when they start the equivalent of syllabic babbling, they do it with their hands.
Research suggests that “manual babbling” emerges around the same time as vocal babbling (Petitto and Marentette 1991). But the first signed words might appear earlier. A study of hearing babies born to deaf parents reported that babies made their first recognizable sign at an average age of 8.5 months (Bonvillian et al 1983). One baby signed as early as 5.5 months.
We should be cautious about interpreting these results, because the study was small and subject to sampling error. But even if these babies happened to be a particularly “fast” group, the results still tell us that some babies are ready to use signs at an early age.
Other research supports this view. One study tracked the infants of hearing parents from 6 to 24 months. Even at the beginning of the study, some babies were already using spontaneous gestures to communicate (Crais et al 2004).
And experiments suggest that very young babies are interested in dialogue. By 6 to 12 weeks old, babies are more likely to coo, smile, and move their hands when their parents make eye contact with them (Crown et al 2002). They also seem to like taking turns, waiting for their parents to stop talking before they begin with a “reply” (Bloom et al 1988).
This doesn’t mean you should start using baby sign language with your newborn. It takes months for babies to develop the motor control necessary to make hand signals.
But the research does suggest that even very young babies may pay attention to--and possibly learn about--your communicative gestures.
How do I begin?
After reading the scientific literature, I suspect that the best way is to pay close attention to your baby and discover what signs he might invent on his own. Your baby may be gesturing and signing already.
In fact, Linda Acredolo’s research on baby sign language was inspired by the spontaneous signing of her baby daughter.
Acredolo and her baby were visiting a doctor’s office where there was a fish tank. When the baby saw the fish, she began puffing air out of her cheeks. Acredolo couldn’t figure out the connection until later that night, when she and the baby were engaged in their regular bedtime ritual of blowing on the fish toys that hung from a mobile above the crib (Acredolo and Goodwyn 1998).
So I think it makes sense to build on what your baby is already doing naturally, and perhaps add a few easy-to-parse, representational gestures yourself.
But keep in mind: Whenever you use a sign, be sure to speak the word(s) that go with it.
The idea isn’t to replace spoken language, but rather to supplement it. That’s what parents did in the experiments described above.
For more information about the ways that babies learn language, see my article
"Baby talk 101: How infant-directed speech helps your baby learn to talk."
References: Baby sign language
Acredolo, LP and Goodwyn SW. 1988. Symbolic gesturing in normal infants. Child Development 59: 450-466.
Acredolo L and Goodwyn S. 1998. Baby Signs. Chicago: Contemporary Books.
Crais E, Douglas DD, and Campbell CC. 2004. The intersection of the development of gestures and intentionality. J Speech Lang Hear Res. 47(3):678-94.
Goodwyn SW, Acredolo LP, and Brown C. 2000. Impact of symbolic gesturing on early language development. Journal of Nonverbal Behavior. 24: 81-103.
Oller DK. 2000. The emergence of the speech capacity. Lawrence Erlbaum.
Iverson JM and Goldin-Meadow S. 2005. Gesture paves the way for language development. Psychological Science 16(5): 367-371.
Iverson, J.M., Capirci, O., Volterra, V., & Goldin-Meadow, S. (in press). Learning to talk in a gesture-rich world: Early communication of Italian vs. American children. First Language.
Johnston JC, Durieux-Smith A and Bloom K. 2005. Teaching gestural signs to infants to advance child development: A review of the evidence. First Language 25(2): 235-251.
Kirk E, Howlett N, Pine KJ, Fletcher BC. 2012. To Sign or Not to Sign? The Impact of Encouraging Infants to Gesture on Infant Language and Maternal Mind-Mindedness. Child Dev. 2012 Oct 3. doi: 10.1111/j.1467-8624.2012.01874.x. [Epub ahead of print]
Meins E, Fernyhough C, Fradley E, and Tuckey M. 2001. Rethinking maternal sensitivity: Mothers’ comments on infants’ mental processes predict security of attachment at 12 months. Journal of Child Psychology and Psychiatry and Allied Discipline 42: 637-648.
Petitto LA and Marentette PF. 1991. Babbling in the manual mode: Evidence for the ontogeny of language. Science 251: 1493-1496.
Puccini D and Liszkowski U. 2012. 15-Month-Old Infants Fast Map Words but Not Representational Gestures of Multimodal Labels. Front Psychol. 2012;3:101. Epub 2012 Apr 3.
image of gesturing baby boy and father by David R Tribble / wikimedia commons
Content last modified 11/12