There is little evidence that infants learn from infant-oriented educational videos and television programming. This 4-week longitudinal experiment investigated 15-month-olds' (N = 92) ability to learn American Sign Language signs (e.g., patting head for hat) from at-home viewing of instructional video, either with or without parent support,…

Findings are presented from the first randomized control trial of the effects of encouraging symbolic gesture (or "baby sign") on infant language, following 40 infants from age 8 months to 20 months. Half of the mothers were trained to model a target set of gestures to their infants. Frequent measures were taken of infant language…

Naturalistic studies show that children can create language-like communication systems in the absence of conventional language. However, experimental evidence is mixed. We address this discrepancy using an experimental paradigm that simulates naturalistic sign creation. Specifically, we tested if a sample of 6- to 12-year-old children (52 girls…

Compared comprehension of novel communicative signs to assist 2.5- and 3-year-old humans, chimpanzees, and orangutans find hidden objects during a hiding-finding game. Found that children at both ages performed above chance with all signs. No ape performed above chance for any signs not known before the experiment despite three times as many…

Channel properties of the deaf children's gesture language are discussed in the light of their communicative behavior. (Author)