Baby sign language offers children with Down syndrome a powerful communication bridge during the critical period when they understand far more than they can verbally express. Research consistently demonstrates that teaching manual signs alongside spoken words does not delay verbal speech development—in fact, it often accelerates it. A landmark 1996 study by Launonen found that children with Down syndrome who received intervention including manual signs had average vocabulary at age three equal to a control group at age four, with enhanced speech compared to controls who did not receive signing instruction.
Consider a 14-month-old with Down syndrome who can follow simple directions and clearly wants to communicate but cannot yet form words. This child might use the sign for “more” during meals or “all done” when finished playing, reducing frustration for both child and caregivers while building the cognitive foundation for spoken language. The motor speech area in the brain develops more slowly in children with Down syndrome, but their ability to produce manual signs often develops on a more typical timeline—making sign language an effective tool rather than a crutch. This article examines the research behind signing with children who have Down syndrome, explores developmental timelines and realistic expectations, discusses practical approaches to implementation, and addresses common concerns parents encounter along the way.
Table of Contents
- Why Does Sign Language Help Children with Down Syndrome Communicate?
- Communication Milestones: What to Expect and When
- Research Evidence: Does Signing Actually Work?
- Building Vocabulary Over Time
- Looking Ahead: From Signs to Speech and Beyond
- Conclusion
Why Does Sign Language Help Children with Down Syndrome Communicate?
Children with Down syndrome typically experience a significant gap between receptive language (what they understand) and expressive language (what they can say). First words occur on average at 16 months—approximately six months later than typically developing children—and the 10-word stage is reached around 2.25 years of age, representing a 1.25-year delay. This gap creates frustration. A child who understands that it’s time for lunch but cannot ask for their favorite food may resort to crying or disruptive behavior simply because they lack the tools to express themselves.
Sign language closes this gap by leveraging motor skills that develop earlier than the fine oral motor control required for speech. Research published in PMC in 2016 found that baby signs produced by children with Down syndrome predict their spoken vocabulary size one year later, suggesting that signing actively supports rather than replaces verbal development. When researchers added signed-only vocabulary to spoken vocabularies of children with Down syndrome, group differences with typically developing children were no longer statistically significant. The use of simultaneous signs with spoken words leads to less frustration and decreased disruptive behavior in children with Down syndrome. However, this benefit depends on consistent implementation—occasional signing during moments of crisis will not provide the same communication foundation as regular, everyday use throughout daily routines.
Communication Milestones: What to Expect and When
Understanding typical developmental timelines for children with Down syndrome helps parents set realistic expectations and recognize progress. Intentional communication—including pointing, gestures, signs, eye contact, and joint attention—develops around 8-10 months of age. This milestone indicates readiness to begin introducing simple signs, though some children may benefit from earlier exposure. Two-word phrases typically consolidate around age three for children with Down syndrome, with average vocabulary at that point reaching 50-55 words.
By 72 months (six years), children with Down syndrome typically have 300-400 words, compared to several thousand for typically developing peers. These numbers can feel discouraging, but context matters: the goal is not to match typical development but to maximize each child’s communication potential. A child with 50 words and 30 functional signs at age three has vastly more communicative power than one with 50 words alone. However, if your child shows minimal interest in communication by 12 months or makes no attempts at gestures or signs by 18 months, consult with a speech-language pathologist who has experience with Down syndrome. early intervention programs—which many children with Down syndrome already access—often incorporate signing as standard practice, and professionals can tailor approaches to your child’s specific needs.
Research Evidence: Does Signing Actually Work?
The evidence base for signing with children who have Down syndrome is substantial and reassuring. The Launonen study from 1996 remains influential, demonstrating that children receiving signing intervention not only matched but exceeded control group performance in vocabulary development. This study helped shift professional opinion away from earlier concerns that signing might discourage verbal speech. More recent research continues to support these findings. Sign language is now recognized as effective augmentative and alternative communication (AAC) that does not hinder but may promote spoken language development in this population. The mechanism appears straightforward: signing provides successful communication experiences that reinforce the value of communication itself, motivating children to continue developing their skills across modalities. In November 2025, UC Davis launched a major $5.5 million NIH-funded study led by Professor Angela John Thurman to build a roadmap for communication support for children with Down syndrome. This five-year project will provide additional evidence and practical guidance for families and professionals. Such investment reflects growing recognition that communication support is a critical need for the approximately 6,000 babies born with Down syndrome each year in the United States. ## How to Start Teaching Signs to a Child with Down Syndrome Begin with signs that matter to your child—typically food, drink, and comfort items. The sign for “more” is often a first choice because it applies across contexts: more food, more tickles, more book reading. Pair every sign with the spoken word, maintaining eye contact and placing your hands where your child can see them clearly. Repetition matters more than variety; five signs used consistently throughout daily routines will build stronger communication skills than twenty signs introduced occasionally. Many parents wonder whether to use American Sign Language (ASL), Signed Exact English (SEE), or simplified baby sign systems. For most families, ASL provides the best long-term value because it connects to a complete language system and a Deaf community your child could potentially engage with later.
However, simplified baby signs or modified versions of ASL signs are perfectly acceptable starting points. The comparison that matters is not which system you choose but whether you use it consistently. Physical prompting—gently guiding your child’s hands to form signs—is often necessary and appropriate for children with Down syndrome, who may need more hands-on support than typically developing peers. Occupational therapists and speech-language pathologists can demonstrate techniques that support learning without creating prompt dependency. ## Common Challenges and How to Address Them The most significant barrier to successful signing is inconsistency. Children with Down syndrome need more repetitions to learn new skills, and signing that stops when it becomes inconvenient sends mixed messages about its value. If grandparents, daycare providers, or other caregivers are not signing, the child receives input only during limited hours with parents. Share resources with everyone in your child’s life and demonstrate the signs you are teaching. Motor planning difficulties can make sign production challenging for some children with Down syndrome. A child may understand a sign and want to use it but struggle to coordinate the hand movements. Accepting approximations—a loose handshape that resembles the target sign—maintains communication momentum while motor skills develop. Occupational therapy can address fine motor challenges that affect sign production. Some children with Down syndrome also have hearing loss, which affects approximately 75% of this population to some degree. If your child has hearing loss, sign language becomes even more valuable, but you may need professional guidance to ensure your approach accounts for both conditions. Do not assume a lack of response to spoken words indicates cognitive limitations when hearing may be the issue.
Building Vocabulary Over Time
Early signing typically focuses on nouns (milk, ball, dog) and simple action words (more, all done, help). As your child’s signing vocabulary grows, introduce signs for feelings (happy, sad, hurt), social words (please, thank you, sorry), and descriptors (big, hot, dirty).
This expansion mirrors how spoken vocabulary develops and gives your child increasingly nuanced ways to express themselves. For example, a three-year-old with Down syndrome might progress from signing “hurt” to signing “hurt” while pointing to a specific body part, to eventually combining signs like “head hurt.” This progression—from single signs to location specification to two-sign combinations—represents genuine language development, not merely gesture imitation.
Looking Ahead: From Signs to Speech and Beyond
Most children with Down syndrome transition naturally from signing to speech as their oral motor skills develop, keeping useful signs for emphasis or when speech is difficult to understand. This transition does not require deliberate fading of signs; children typically shift to speech when it becomes easier than signing for them.
An estimated 400,000-600,000 people currently live with Down syndrome in the United States, and the vast majority use spoken language as their primary communication mode by adulthood. The ongoing UC Davis research project and similar studies will continue refining best practices for supporting communication development. What remains clear from existing evidence is that early, consistent signing gives children with Down syndrome more opportunities to communicate successfully—and those successful experiences build the foundation for all future language development.
Conclusion
Baby sign language provides children with Down syndrome an effective communication tool during the critical years when verbal speech is still developing. Research spanning decades demonstrates that signing does not delay speech but often facilitates it, reducing frustration while building vocabulary.
The key factors for success are consistency, patience, and involving everyone in the child’s life. Starting with a few high-motivation signs, pairing them always with spoken words, and accepting approximations while motor skills develop will set your child on a path toward successful communication. Work with your early intervention team or a speech-language pathologist to tailor approaches to your child’s specific needs, and remember that every sign learned represents genuine language progress.