Baby sign language (science or hype?)

Recap: What is “baby sign language”?

I made an attempt at defining this concept in the last post, which I’ll reproduce here: baby sign language is signing between (hearing) parents/caregivers and young children, where the signs are either from a real sign language like ASL, are idiosyncratic inventions of the family using them, or are some combination of both. Even if the signs come from a legitimate sign language, they’re often simplified, and the fuller grammar is not usually taught to/learned by parents or their children.

In this post, I’ll talk about baby sign timelines and tips, and then we’ll look at the supposed benefits versus the science.

Timelines

Taking into account your baby’s development, signing with them might roughly follow this path:

• 6-9 months: Introduce basic, highly relevant signs
  • At this age, babies really start associating language (verbal or signed) with their world
  • Their long-term memory is now primed to start retaining the language heard around them
  • Their motor skills and hand-eye coordination are growing more precise
• 7-12 months: Baby is likely to start signing back to you
  • Their first signs will be physical approximations – they may be less detailed and only roughly resemble the sign’s actual shape or location – and they may also be semantic approximations – for example, where the meaning of the sign is broader than the standard/adult meaning (a phenomenon called overextension).
    • My son Ryden’s first sign was more. He started using it in the same context in which we modeled it – during meals to indicate “I want more food” – but then began using it in many different contexts, all the time. From these various contexts, we guessed his meaning was something like “do / keep doing the thing that I like / that makes me happy”. His usage was still related to the concept of more, but it also communicated things that would be captured by a larger variety of expressions in standard ASL. 
• 12+ months: Introduce slightly more complex (and maybe abstract, but still relevant) signs
• ~2 years: Child may start stringing signs together, and combining them with speech

Still, like with spoken language, an infant will grasp a sign’s meaning before they’re able (or willing) to produce the sign themselves.

I started signing for Ryden when he was about 5 months old. Signs I used daily were milk, drink, sleep, food/eat, more, read, book, mommy, water, change, diaper, and bath; and I included some of these into the two-word phrases drink milk, read book, more food, and change diaper. Signs I used a bit less frequently, but still repeatedly, were daddy, hungry, cereal, sing/song/music, outside, I love you, play, all done, and up. 

Ryden always seemed to pay extra attention when I used a sign (he grew quiet and still, looked intently at my hands and face), and I could tell by way he responded at 10-11 months that he recognized all of them. But except for adopting the “more” sign around 11 months, he didn’t produce any others. By then he had begun voicing some semi-intelligible words anyway, so I kind of dropped off signing to him.[1]

Tips

Here are some common-sensical tips for signing with your baby:

1. Be consistent and contextual.
   • Use the same sign for the same thing. Sign at the time of the event.
2. Be open and encouraging to any efforts.
   • As mentioned, your baby’s first attempts will be approximations. They may even make up a totally different “sign”.
     • Before Ryden began using the more sign, he would just open his mouth really wide and whine impatiently in between spoonfuls (he’s been a voracious eater since the start of solid food). Even though he wasn’t signing, his desire was very clearly (if not pleasantly) communicated.
     • When he began signing more, he would kind of slap his hands together (like a clap, but with his fingers slightly curled) – definitely an approximation of the precise adult sign.
3. Make signing fun.
   • Use it in games; be excited; don’t scold if your baby doesn’t sign back. 
4. Be multimodal.
   • Say the word when you are signing it.
5. Be repetitive.
   • Incorporate the signs into your daily routines.
6. Use signs for tangible objects and actions over more general and abstract words/concepts, and choose signs for things that interest your baby.
   • Try milk, dog, and crawl before yes or please.

Proposed benefits (versus actual research)

Infants are little sponges. They start soaking up the language around them immediately – as soon as they’re born (and newer research points even earlier, to in-utero). At 6 months old, they comprehend considerably more than one might imagine. Language production, however, takes a while longer. The earliest that babies produce their first spoken words is 8-10 months. More often it’s closer to one year. (Ryden’s first word, cup [“kah!”], was around 11 months.) Proponents of baby sign language claim that babies can produce signs before speech. According to this claim, an infant’s hand/arm muscles develop before their articulatory system. Thus one of the main motivations for teaching a preverbal child some basic signs is to enable them to communicate sooner.

The babysignlanguage.com website groups the benefits of baby signing into three types, and most of the other material I’ve seen proposes benefits that fall into these categories.

Practical

If babies have the tools to communicate what they want, they will use those tools instead of crying and tantrum-ing. Parents will be able to understand when their child wants Cheerios, or has a poopy diaper, or is tired, and respond appropriately. There is less frustration all around.

Emotional

Increased communication between parents and their preverbal children tightens the bonds between them. Parents report feeling closer to their babies, better able to anticipate and understand their needs. And their babies, secure in this close connection, are generally less fussy.

Cognitive

Advocates assert that signing with your baby improves their long-term cognitive development. Per babysignlanguage.com, this means a +12 IQ point advantage, a larger speaking vocabulary, earlier reading and higher reading comprehension, and better grades. 

Bill White and Kathleen Harper of “Happy Baby Signs” also state that signing with babies:

• “Accelerates language acquisition.” Babies that sign usually speak earlier and have larger vocabularies;
• Employs more diverse brain pathways like the visual and kinesthetic (in addition to the auditory) to process language[2]; and (again)
• “May actually improve a child’s IQ.” Research that tracked signing babies as they grew found that those children, at eight years old, scored an average of 12 points higher in IQ testing than a non-signing control group (after accounting for socioeconomic differences). 

This sounds awesome. I want a sweeter, brainier, more communicative baby! So let’s delve a bit further.

The practical and emotional benefits seem obvious. However, they both hinge on the assumption that infants really can and do learn to sign before they start communicating verbally – or even with gestures (like pointing[3]). It’s actually unclear whether this is true. I recommend reading this article on the subject, but here are the basic points:

• It’s difficult to determine what counts as a baby’s first real spoken words (versus the syllables they’ve been babbling up to that point), because their early attempts are necessarily imperfect – approximations.
  • When your baby says “dada” for daddy, should that be considered a real word? If you observe that your little one says “dada” whenever he/she sees dad, it makes sense to count “dada” as their legitimate word for daddy. But at this stage, “dada” could also be meaningless babble. Thus “researchers who study the emergence of speech must find ways to sift those instances out. They need to establish a set of objective criteria for recognizing an utterance as a spoken word.”
  • Similarly, (as discussed above) a baby’s first signs are going to be approximations.
  • Comparing the onset of infant signing to infant speaking requires using the same criteria for what counts as a word.
• If infants really can learn to sign before they learn to speak, we should see evidence that deaf babies and babies of deaf parents sign earlier than hearing babies. But there aren’t any solid studies (with large sample sizes) demonstrating this.

As for the long-term cognitive benefits… again, the research is weak. The most frequently-cited work in this area is that by Linda P. Acredolo and Susan W. Goodwyn (1988, 1998, 2000)[4]. Their studies followed children from infancy to 36 months, and found that the ones who were taught to sign had slightly larger receptive vocabularies than babies in a control group – but only at a couple points in the middle of the study. By the end, differences between the two groups were not statistically significant. 

More recent and well-controlled studies[5] have also failed to uncover longer-term language gains for sign-taught babies.

On IQ, Dr. Gwen Dewar (author of the article referenced above) states: “the relevant research has yet to appear in any peer-reviewed journal. On this question, it’s safe to say that the jury is still out.”

Wikipedia also underlines the questionable nature of baby sign language benefit claims on the internet by detailing two studies conducted on sites making these claims. In the first study, over 90% of the information was opinion pieces or marketing products, with no research backing. The second study found only 10 articles out of 1747 (!) that presented research on the developmental effects of baby signing. And the consensus among those 10 articles was that baby signing doesn’t improve linguistic production or caregiver-child relationships. (That said, neither is there evidence that teaching babies to sign could be detrimental.)

My take

My brief takeaway is – sign with your baby if it interests you and seems fun. I enjoyed learning a bit of ASL just for myself. But temper your expectations. Don’t expect your child to sign back quickly / much / at all before they start on verbal language (unless maybe you AND other caregivers sign to them constantly). And don’t expect that it will later transform them into a linguistic super-genius.

Resources / Further reading

• Nice article shedding a healthy scientific skepticism on the benefits of baby signing (I linked to another one of her articles above): https://www.parentingscience.com/baby-sign-language.html
  • Especially check out the part on iconicity – interesting stuff. 
• ASL / baby sign dictionaries:
  • Large online collection of videos: https://www.signasl.org/ 
  • “Baby sign language” videos (choose other categories in the right-hand dropdown) 
• Baby sign language dictionary: https://www.babysignlanguage.com/dictionary/

[1] All babies are different, but my main guess as to why he didn’t produce any other signs before starting speech is that he needed more input – more than the few words I regularly used, and from more people (his father, our nanny, etc.).

[2] From White, W.P. and Harper, K.A. (2017). Signs of a Happy Baby: The Baby Sign Language Book. United States: Morgan James Publishing. [Google Books link] (pp. 11-12):

“When you say the word ‘milk’, babies hear the word […] That auditory stimulus travels from the ears to the language center of the brain to be stored as the word ‘milk’. However, […] when babies watch their parents sign milk and hear them say the word, […] [they] also have the wonderful opportunity to see what the word looks like. This additional visual information travels from the eyes back to the occipital cortex, which is commonly called the visual center of the brain. […] Your baby also knows what the word ‘milk’ feels like. When babies start signing back using their hands, that is what is called kinesthetic information. The motion of their hands and arms is being controlled by a third part of the brain called the motor cortex.”

[3] Do not underestimate the communicative powers of pointing! As soon as Ryden started pointing (between 11-12 months), it became much easier to intuit what he wanted or was interested in – because he simply pointed at it.

[4]
(1) Acredolo, L.P. and Goodwyn, S.W. (1988). Symbolic gesturing in normal infants. Child Development 59: 450-466.
(2) Acredolo, L.P. and Goodwyn, S.W. (1998). Baby Signs. Chicago: Contemporary Books.
(3) Goodwyn, S.W., Acredolo L.P, and Brown, C. (2000). Impact of symbolic gesturing on early language development. Journal of Nonverbal Behavior. 24: 81-103.

[5]
(1) Johnston, J.C., 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.
(2) Kirk, E., Howlett, N., Pine, K.J., and Fletcher, B.C. (2013). To Sign or Not to Sign? The Impact of Encouraging Infants to Gesture on Infant Language and Maternal Mind-Mindedness. Child Dev. 84(2):574-90.
(3) Seal, B.C. and DePaolis, R.A. (2014). Manual Activity and Onset of First Words in Babies Exposed and Not Exposed to Baby Signing. Sign Language Studies 14(4): 444-465.