Parents use baby sign language because infants can control their hands months before they can control their vocal cords. Babies can learn simple signs as early as 6 months old, while most first spoken words don’t appear until 12 months or later. That gap creates a window where a baby has wants and thoughts but no way to express them beyond crying. Teaching a few basic signs gives infants a tool to communicate specific needs, which reduces frustration for everyone in the household.
Closing the Communication Gap
Crying is a baby’s primary mode of communication, but it’s blunt. A cry can mean hunger, pain, boredom, or a wet diaper, and parents are left guessing. Signs work differently: like spoken words, they can specify exactly what a child wants. A baby who signs “milk” or “more” is giving their caregiver precise information, which leads to faster, more effective responses.
In controlled experiments published in the Journal of Applied Behavior Analysis, researchers found that when infants were taught signs, crying and whining were directly replaced by signing. The babies didn’t just add a new skill on top of existing behavior. They shifted from a vague, distressing signal to a clear, specific one. This matters for parents too. Research on parental stress consistently shows that infant crying triggers a strong physiological stress response in caregivers. Signing offers a form of communication that both parent and baby find less aversive.
It Doesn’t Delay Speech
The most common concern parents have is whether signing will make a baby “lazy” about learning to talk. The research consistently points in the opposite direction. A well-known training study by Goodwyn, Acredolo, and Brown found that infants who were systematically exposed to baby signs starting around 11 months developed better expressive and receptive language skills by age 2, compared to infants who received either verbal-only training or no training at all.
A 2023 study published in PubMed looked at children learning both ASL and spoken English and found that ASL vocabulary size positively correlated with spoken English vocabulary size. Children with large sign vocabularies were actually more likely to have spoken vocabularies in the normal range for hearing children their age. The researchers concluded that if any causal relationship exists between sign exposure and spoken language, the effect appears to be positive, not negative.
The American Academy of Pediatrics echoes this: as long as signing doesn’t replace speaking (meaning you still talk to your baby while you sign), it won’t interfere with verbal development.
Changes in How Parents Interact
Something interesting happens to parents who sign with their babies. Research comparing baby-signing mothers to non-signing mothers found that both groups responded to their infants’ gestures at similar rates. The signing mothers weren’t necessarily more attentive in a general sense. But the quality of their responses shifted in a subtle and meaningful way.
Baby-signing mothers used significantly more “internal state” language when responding to their infants’ gestures. They were more likely to say things like “you want that” or “you need this,” using words that acknowledged their baby’s desires and intentions. On average, signing mothers produced about 12 internal state responses during observed interactions, compared to about 8 for non-signing mothers. They were also more likely to use words like “want” and “need” specifically.
Researchers interpreted this as a sign that mothers who use baby sign tend to view their infants as beings with their own intentions and preferences, rather than just responding to surface-level cues. This “mind-minded” approach to parenting, where you treat your baby as someone with an inner life, is linked to stronger emotional attachment and better developmental outcomes over time.
When to Start and What to Expect
Most pediatric guidance suggests introducing signs when your baby is around 6 to 8 months old. That’s the age when babies typically start mimicking gestures like waving and clapping. If your baby is repeating your hand movements, they’re likely ready to start learning signs. Don’t expect them to sign back immediately, though. Babies need time to develop the hand coordination to form signs on their own, and there’s usually a lag of several weeks between when you start modeling a sign and when your child first produces it.
Most parents start with a handful of high-value signs: “milk,” “more,” “all done,” “eat,” and “help” are common first choices because they map onto situations that come up repeatedly throughout the day. Repetition in context is key. You sign “milk” every time you offer milk, and eventually, the connection clicks. Typically developing children use baby signs for a relatively short window before spoken words take over, so this isn’t a years-long commitment. It’s a bridge that covers a few critical months.
Benefits for Children With Developmental Delays
Baby sign language has particular value for children at higher risk for language delays, including those with developmental disabilities or sensory impairments. A large body of research links language delays to later behavior problems. The logic is straightforward: a child who can’t communicate what they need is more likely to act out. Because children can learn signs months before they can produce spoken words, signing offers an earlier on-ramp to communication for kids who might otherwise wait much longer.
Research on children with Down syndrome has shown that baby signs (as distinct from the spontaneous gestures all children produce) can predict later vocabulary size. For children whose speech development follows a slower trajectory, having a way to make themselves understood during that extended pre-verbal period can meaningfully reduce daily frustration and its downstream effects on behavior.
For typically developing children, the practical benefit is simpler but still real: a few extra months of clear communication during a stage when tantrums often stem from the inability to say what they mean.