The Benefits of Baby Sign Language

At nine months old, most babies can't say a single word. What they can do, if you give them the vocabulary, is open and close one small fist when they want milk. Or tap their fingers together when they want more. Or wave a flat hand away from their chest to say they're finished.

This is the idea behind baby sign language. Not a formal language system. Not full American Sign Language taught properly, though some families go that route. Just a handful of simple gestures mapped to things babies want to talk about. The gap between what a baby understands and what a baby can actually say aloud runs roughly six to twelve months. Signs help close it.

Most parents who ask about signing want to know whether the benefits are real or overclaimed. The honest answer sits in the middle. Some of the claims on parenting websites are oversold — signing won't make your baby smarter, and it won't give her a vocabulary three times larger than her peers. The well-documented benefits are smaller than that, but they're genuine.

The Gap Between Understanding and Speaking

By around eight or nine months, most babies understand a surprising amount of what you say. They know their name. They recognize “no.” They turn when you mention the dog or the bottle. Their receptive language — the part that takes words in — is weeks or months ahead of their productive language, the part that sends words out.

That mismatch shows up as frustration. A baby who clearly wants something but has no way to name it has to resort to pointing, fussing, or crying until the adult runs through the right guesses. Parents who've watched this cycle play out twenty times before dinner know exactly how exhausting it is for both sides.

Signs don't close the gap because babies learn to sign faster than they learn to speak. They close it because the motor system needed for a gesture matures earlier than the motor system needed for speech. Shaping a hand into a sign is easier than coordinating lips, tongue, breath, and vocal cords to produce a word. A nine-month-old can reliably make a simple sign. That same nine-month-old is still months away from “milk” coming out as anything but “ba.”

What the Research Actually Shows

The most-cited work on baby signing comes out of the University of California, Davis, where Linda Acredolo and Susan Goodwyn ran a series of trials starting in the 1980s and followed the children into toddlerhood. In their original work, babies taught symbolic gestures between eleven and fifteen months had slightly larger spoken vocabularies at age two than matched non-signing peers. The gap was modest — twenty to thirty extra words — but real.

Later independent work cooled the claims. A randomized controlled trial from the University of Hertfordshire, published in 2013, taught one group of infants baby signs and compared them with non-signing control groups at twenty, twenty-four, and thirty months. By twenty-four months, the children had caught up to each other. Signing hadn't produced a lasting language advantage. It also hadn't produced any harm.

Across the literature, one finding does hold up repeatedly. Families who use signs report fewer moments of helpless frustration between nine and eighteen months — the peak window for pre-verbal communication breakdowns. Parents feel more confident reading what their baby wants. Babies have more ways to participate in daily exchanges. That isn't a spectacular IQ boost. It's a calmer kitchen floor at dinnertime. For most families, that's the reason that matters.

When Babies Can Actually Start Signing

You can start showing signs much earlier than a baby can produce them. Many families introduce their first two or three signs around six months, alongside the start of solid foods. The baby won't sign back for a while. That's fine. The exposure phase is normal and important.

Most babies produce their first reliable sign somewhere between eight and eleven months. A few do it earlier. Some wait closer to a year. The range is wide, and like almost everything in the first year of infant development, there's no single right timeline. A baby who signs at seven months isn't gifted. A baby who waits until twelve months isn't behind. Both are typical.

What you're watching for isn't a perfect reproduction of the sign. Early attempts are approximations. The “milk” sign — one hand opening and closing — usually looks more like a general fist-clench at first. The “more” sign — fingertips tapping together — often comes out as two flat hands patting each other. If the gesture happens in the right context and you respond, the baby has made a communicative move. The motor refinement follows over weeks.

The Handful of Signs That Do the Most Work

You don't need to teach dozens of signs to see the benefit. A small core set — five to eight signs that cover the most common daily requests and observations — gives a baby most of the usable vocabulary she needs in the pre-verbal window.

The signs families find most useful tend to cluster around a few themes:

• Feeding: milk, water, eat, more, all done

• Daily care: sleep, diaper, bath, help

• People and things she notices: dog, cat, bird, book, light

• Feelings she can flag: hurt, hot, cold

“More” and “all done” are often the first two families teach, because they're useful at every meal and they're easy for small hands to form. “Milk” is a strong third, since most babies have a lot to say about milk. “Help” and “hurt” come later but matter disproportionately. A twelve-month-old who can tell you her foot hurts because a sock seam is digging in is a twelve-month-old who doesn't have to cry for forty minutes first.

You can use signs from American Sign Language (which is what most baby-signing books teach) or invent your own. Both work. The research hasn't found a meaningful difference between the two approaches in terms of language outcomes. ASL signs have the advantage that other people may recognize them — a grandparent or a daycare provider can pick up a few without coaching.

How It Actually Looks in Daily Life

The way most families teach signs isn't through sit-down lessons. It's through steady repetition inside the moments where the word naturally comes up.

You sign “milk” while you say “milk” and hand over the bottle. You sign “more” while you say “more” when you give a second spoonful. You sign “all done” while you say “all done” at the end of the meal and lift her out of the high chair. The baby sees the sign hundreds of times, paired with the object and the word, before she tries to produce it herself.

Two small habits make the learning stick. Use the sign in full view of the baby, not off to the side. And always pair it with the spoken word — never sign silently, hoping she'll pick up just the gesture. Signs are not a replacement for talking. They're an accessory language that rides alongside spoken words while the vocal system is still under construction.

The strongest predictor of language growth in the first two years isn't a specific method. It's the total amount of warm, responsive talk a baby hears from the adults around her.

This is also why parents who worry that signing will somehow delay speech can relax. The consistent finding across decades of study is that signing babies end up speaking at about the same time as their peers, sometimes slightly earlier. The signing doesn't replace the speech circuit. It runs parallel to it while it ripens.

What Signing Doesn't Do

Honest expectations go a long way. Signing will not make your baby verbal earlier in any dramatic sense. It will not give her a measurable cognitive edge that lasts into preschool. It will not make the second half of her first year tantrum-proof.

What it does do is narrow a specific, frustrating window in which your baby clearly wants to tell you something and has no reliable way to do it. That narrowing is worth something on its own. Parents often describe the moment their child made her first successful sign as surprisingly emotional — a small but unmistakable sense of her coming into focus as someone with opinions and preferences she can now share.

A few families try signing and drop it after a month or two because they don't see progress. That's common and not a failure. Some babies take much longer to show a sign back. Some families find the daily effort doesn't match the payoff for their particular household. Both are fine outcomes. Signing is an optional tool, not a developmental requirement.

When to Ease Off

Most families naturally retire baby signs somewhere between fifteen and twenty-four months, as spoken words start to take over. The baby may keep using the occasional sign for a month or two longer, especially for favorites like “more,” but the overall pattern is that signs fade as speech arrives.

You don't need to actively stop signing. The baby drops what she doesn't need. If you find your toddler still using a sign long after she could say the word, she's probably using it the way adults use hand gestures — for emphasis, or to make sure she's heard. That's normal, and there's no developmental concern in continuing.

One caveat worth knowing. Families sometimes ask whether baby signing is still helpful for toddlers who are late talkers. The general answer from speech-language pathologists is yes, with the caution that a persistent speech delay past two years deserves a professional evaluation rather than more home signing. Signs can be part of a support plan, but they aren't a substitute for assessment when a child isn't following the expected arc of early language development.

Fitting Signing Into the Bigger Picture

Signing works best when it sits inside a broader rhythm of talking, reading, and responsive interaction. A baby who is signed to and also talked to, read to, and listened to will do well. A baby who is signed to in silence, with everything else stripped out, won't get the same benefit — because signs were never the main engine. The main engine is language exposure of every kind.

Reading is a natural pairing. Picture books full of animals and daily objects are a low-effort way to practice signs in context. Point to the dog on the page, sign “dog,” say “dog.” A short list of activities that support infant language development overlaps almost perfectly with the moments where signing slots in naturally.

The same goes for play. Floor time, peekaboo, the small daily loops that babies love — these are all places where a sign can land. You don't need a separate curriculum. Our Milestone Tracker can help you see where your baby is in the broader language and motor arc, which makes it easier to judge whether introducing signs now makes sense or whether she's still a few weeks out.

Parents who've been studying their baby's cues closely are often already halfway to signing without knowing it. If you've been working on how to read your baby's different cries, you've been building exactly the pattern-recognition skill that makes signing click. Signs are just a structured extension of that same two-way reading.

Frequently Asked Questions

Does baby signing delay speech?

No. This is the most common worry parents raise, and the evidence on it has been consistent for more than thirty years. Babies who sign do not learn to talk later. Across randomized trials, signing babies reach typical speech milestones at the same age as non-signing babies, and some studies find a slight acceleration in vocabulary during the second year. The underlying reason is that signs and speech use overlapping but distinct brain systems. Using one doesn't starve the other. Think of it as two parallel paths to the same destination rather than a tradeoff.

What age should I start?

Six to eight months is when most families start showing signs, because that's when babies begin paying real attention to hand movements and starting solids (which gives “more” and “all done” an immediate daily use). You won't see signs back for a couple of months after you start. That delay is normal. If your baby is closer to nine or ten months and you haven't started yet, it's not too late. You'll often see faster pickup because the motor system is more ready.

Do I need a book or a class, or can I just pick up a few signs online?

For a starter set of five to ten signs, a short online tutorial or a diagram chart is usually enough. Most parents don't need a full class. If you want to use real ASL accurately, or if you're planning to sign with a child who is deaf or hard of hearing, seek out a certified ASL instructor or a speech-language pathologist. That's a different situation with different standards. For typical hearing babies learning a handful of request-signs, consistency at home matters more than formal instruction.

My baby is fourteen months old and still not signing. Is something wrong?

Almost always, no. Some babies simply don't take to signing even when it's regularly offered. They may be using other strategies — pointing, pulling you toward what they want, consistent sound patterns of their own — that are serving the same purpose. If spoken language is also coming along on the usual schedule and your baby is showing clear social communication in other ways (eye contact, gesturing, babbling with inflection, responding to her name), there's no cause for concern. If multiple communication channels seem stalled or absent, that's a different conversation and worth raising with your pediatrician.

Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider for personalized guidance regarding your child's health and development.