Sign language in infants and toddlers
This article is about the usage of sign language to communicate with infants and toddlers.

# Development
In the United States, teaching sign language to non-signing families to communicate with their hearing infants and toddlers was developed by Linda Acredolo, professor emeritus of psychology at the University of California, Davis, and Susan Goodwyn, professor of psychology at California State University, Stanislaus.  Their research began in 1982, and produced a 1985 article in Human Development titled Symbolic gesturing in language development: A case study.
Joseph Garcia, an ASL interpreter and a leading proponent of use of ASL in communicating with infants and toddlers, began with his graduate thesis in 1986, an analysis of the role sign language could play early childhood language acquisition.  His research indicated that babies who are exposed to signs regularly and consistently at six to seven months of age can begin using signs effectively by the eighth or ninth month.

# Purpose
These proponents believe that while infants and toddlers have a desire to communicate their needs and wishes, they lack the ability to do so clearly because the production of speech, which requires coordinating the lips, tongue, breath, and vocal cords simultaneously, lags behind cognitive ability in the first months and years of life.  This gap between desire to communicate and ability often leads to frustration and tantrums.  Proponents believe that hand-eye coordination is possible in advance of the acquisition of verbal skills, and that infants can learn to express their needs using simple signs for common words such as "eat", "sleep", "more", "hug", "play", "cookie", "teddy bear", etc., before they are able to produce understandable speech.

# Vocabulary
Proponents have identified two main categories of words used, those which are "need-based" and those which are "highly motivating".

## Need-based
Need-based signs include such signs as "drink", "food", "sleepy", "hot"/"cold", "change me", etc. "Drink" or "thirst" can be expressed by mimicking drinking out of a bottle. "Eating" could be expressed by making a similar motion, or by rubbing one's stomach.

## Highly motivating
Highly motivating signs focuses on items of interest or entertainment to the child, such as signs for "doggy", "toy", "friend", etc. A parent can encourage growth in the child's vocabulary by teaching them signs for items that the child desires and seeks out.

# Systems

## Indigenous sign languages
In this method, vocabulary words which are part of the indigenous sign language of the region are used.  In Australia, the signs are adopted from Auslan (AUstralian Sign LANguage); in America, ASL (American Sign Language) signs are used.  This provides a standard vocabulary which allows others to understand and communicate with the baby using these signs and can provide a basis for the continued study of the indigenous sign language as the child grows older.

## Home-based sign language
Home-based sign language is a system of sign developed individually between infant and caregivers.  Proponents argue that vocabulary from ASL and other formal sign languages can be too difficult for an infant to produce.

# In popular culture
- In Meet the Fockers, Jack (Robert Deniro's character) had taught his grandson "Little Jack" in sign language. The twins that portrayed Little Jack (Bradley and Spencer Pickren), learned sign language from watching Signing Time! videos.