Baby Sign Language: What the Evidence Says

What is baby sign language?

Baby sign language is the use of simple hand signs alongside spoken words, so a baby can communicate before they can talk. A 2014 systematic review by Elizabeth Fitzpatrick and colleagues in First Language defined baby signs as symbolic gestures for objects (arm flapping for "bird"), actions (thumb to mouth for "drink") or states (an index finger dragged down the cheek for "sad"), taught by adults modelling them.

The review draws a clear line: baby signs "are not intended to be used as a language or as a replacement for oral vocabulary but rather only as a symbolic support to spoken language". Some classes borrow signs from a national sign language, and these differ by country. The US National Institute on Deafness and Other Communication Disorders (NIDCD) states that "there is no universal sign language" and that British Sign Language (BSL) "is a different language from ASL", American Sign Language.

Babies gesture anyway

On the revised CDC milestone checklists, which list skills at least 75% of children show by each age, a baby "lifts arms up to be picked up" by 9 months, "waves 'bye-bye'" by 12 months and "points to ask for something or to get help" by 15 months (see when babies clap and wave). A study of 10 children by Jana Iverson and Susan Goldin-Meadow found that many things a child first expressed with a gesture later appeared as words, and concluded that "early gesture may be paving the way for future developments in language".

Does baby sign language help babies talk sooner?

The best evidence says no. The first randomised controlled trial, run by Elizabeth Kirk and colleagues at the University of Hertfordshire, followed 40 babies from 8 to 20 months in four groups of 10: BSL signs, simple baby signs, extra spoken words for the same items, and no intervention. Signing babies learned the signs, some using 17 by 20 months. But they "did not differ from control conditions on language outcomes", and the authors found "no support" for claims that encouraging gesture "accelerates linguistic development".

The trial found one difference in parents. In a closer analysis of 18 mother–baby pairs, mothers who signed "were more responsive to their infants' nonverbal cues and encouraged more independent action by their infant", although overall scores for this kind of attunement did not differ between groups.

The Fitzpatrick review, from the University of Ottawa, screened 1,902 citations and found 10 eligible reports. Only one earlier study, by Susan Goodwyn and colleagues, found better scores on some language measures up to 24 months, with no differences after that. The review concluded that "there is no robust evidence" that baby signing enhances early communication in typically developing children.

Does baby sign language delay speech?

There is no evidence that it does. The Fitzpatrick review found "no evidence was identified to suggest that using baby sign interferes with typical child development", and noted that "no studies reported any adverse effects on typical language development". Its practical conclusion is even-handed: no reason to push parents into signing programmes, and "no basis for discouraging parents who may wish to use symbolic gestures".

One caveat: these studies were of hearing babies with hearing parents. For a baby who is deaf or hard of hearing, sign language is a full language, and the NIDCD advises exposing them to language, "spoken or signed", as soon as possible. It notes that 9 out of 10 children born deaf have hearing parents.

When to start baby sign language

The studies started between 8 and 11 months: the Kirk trial at 8 months, the Goodwyn study at 11 months. That matches when gesture begins anyway; the review places babies' first gestures, usually pointing, at around 8 to 10 months.

Expect a wait before your baby signs back. In a 1993 report from the Goodwyn group, babies taught signs from 11 months produced their first sign at an average of 11.9 months and their first word at 12.6 months (see when babies say mama and dada).

How to teach it

The Kirk trial gave mothers four instructions worth copying:

• Use the signs as often as possible in everyday routines.
• Always say the word with the sign.
• Get your baby's eye contact before you sign.
• Pause afterwards to give your baby time to respond.

Mothers used "more" at mealtimes and beyond: "more tickles", "more book reading", "more singing". The NHS advice on helping a baby learn to talk fits alongside: name and point to things you can both see, and sing action songs such as "Pat-a-cake", because "doing the actions helps your child to remember the words." What comes next is in toddler speech and language milestones.

Baby sign language chart: first signs

These descriptions come from the appendix of the Kirk trial, which gave each word as a simple baby sign and as the BSL sign. BSL and ASL are different languages, so US families using ASL should check an ASL source.

The trial's lists did not include milk, please, help or water. Whatever signs you choose, everyone who looks after your baby should use the same ones.

When to speak to a health visitor or doctor

The CDC lists using "few or no gestures by 12 months of age (for example, does not wave goodbye)" among its signs of autism, and losing gestures or babble a baby once had is a reason to be seen promptly; NICE asks professionals to refer children under 3 with regression in language or social skills (see early signs of autism and a baby not pointing yet). If gestures and sounds are both slow, ask for a hearing check (see a baby not responding to sound).

In the UK, the NHS says to talk to your GP or health visitor if you are worried about speech or language, and that you can refer your child to a speech and language therapist yourself.

Frequently asked questions

What is the baby sign for "more"?

In the Kirk trial's baby-sign set, "more" was the first finger tapped into the upward open palm of the other hand. The BSL version in the same trial was the palm of one hand hitting the back of the other. Pick one version and use it every time you say the word.

Does baby sign language delay speech?

No study has found that it does. A systematic review of signing with hearing babies found no adverse effects on typical language development, and a randomised trial found signing babies' language matched that of babies who did not sign. The same evidence also shows it does not make babies talk sooner.

When should I start baby sign language?

Research programmes started at 8 to 11 months, around when babies begin to gesture by themselves, usually by pointing at about 8 to 10 months. Expect to sign for a while before your baby signs back: in one study that started at 11 months, the average first sign came at 11.9 months.

Is baby sign language the same as BSL or ASL?

Not quite. Baby signs are simple gestures meant to support speech, not replace it, though some programmes borrow signs from BSL in the UK or ASL in the US. BSL and ASL are separate languages, so US and UK sources may show different signs.