Somewhere between the sleepless newborn weeks and the first birthday, most parents run into the promise: teach your baby to sign, and they'll talk sooner, tantrum less, and maybe even test smarter. Baby sign language is a booming little industry built on those claims. So what does the actual research say? The honest answer is more nuanced, and, in a reassuring way, more freeing, than the marketing.
What the studies actually found
The strongest test of a claim is a randomized controlled trial, and baby sign has a few. In one well-known trial, researcher Elizabeth Kirk and colleagues (2013) randomly assigned families to sign with their babies or not, then tracked language development. The result: signing did not significantly accelerate the babies' language or cognitive development compared to controls. Interestingly, the study did pick up effects on parent behavior, mothers who signed tended to be more responsive and encouraging, but the head start in talking that many parents hope for didn't materialize.
Broader reviews reach the same place. A 2014 systematic review by Fitzpatrick and colleagues examined the evidence for gestural signing in typically-developing, hearing infants and found little solid support for the popular claims that it boosts language or IQ. Earlier reviews had already flagged that many confident marketing statements weren't backed by rigorous studies.
In short: for a typically-developing, hearing baby, the evidence that signing makes them talk earlier or think smarter is weak.
The good news hidden in the research
Before you toss the idea, notice two things the research also shows:
It doesn't hurt. A common worry is that signing might delay speech, why bother talking if you can gesture? Studies consistently find no such effect. Babies who sign go on to talk right on schedule. So there's no risk in trying it.
The interaction is the point. The one consistent signal in the research is about how parents behave when they sign, more eye contact, more responsiveness, more back-and-forth attention to what the baby is "saying." That responsive, tuned-in interaction is exactly what does drive language. Signing can be a nice scaffold for it. But it's the connection, not the hand shapes, doing the work, and you can get that same connection through talking, reading, and responding, with or without signs.
A realistic, low-pressure approach
If you enjoy baby sign, and many families genuinely do, here's how to do it in a way that matches the evidence:
- Keep it functional and small. A handful of useful signs ("more," "milk," "all done," "help") can genuinely cut down on frustration during the pre-verbal stretch. You don't need a 100-sign curriculum.
- Always say the word out loud. Sign and speak together, every time. The spoken word is what you actually want to grow.
- Treat signs as conversation, not flashcards. Respond to their sign like you'd respond to a word, "You want more? Here's more!" That back-and-forth is the real ingredient.
- Drop it guilt-free if it's not your thing. Skipping baby sign will not put your child behind. Reading a simple, realistic book together and answering their babbles does everything signing hoped to do.
The bottom line
Baby sign language isn't magic, and it isn't a shortcut to an early talker or a bigger IQ, the research just doesn't support those promises. But it's harmless, it can ease some real-world frustration, and it can nudge you toward the responsive, face-to-face interaction that genuinely builds language. Do it if it's fun. Skip it if it's not. Either way, the thing that matters most is the same: paying warm, back-and-forth attention to your baby's attempts to communicate, however they're making them.
Sources: Kirk, Howlett, Pine & Fletcher (2013), Child Development, on baby sign and maternal responsiveness; Fitzpatrick, Thibert, Grandpierre & Johnston (2014), "How HANDy are baby signs? A systematic review." This article is general information, not a substitute for advice from your pediatrician or a speech-language pathologist.