Why should signing facilitate speech development?
Several studies suggest that pairing signs with words leads to a transfer of learning, and the acquisition of spoken words (Bricker 1972; van Biervliet 1977; Penner & Williams 1982). A study by Reid (1984) found that not only were signs learned more quickly than words, but that children who learned signs first, subsequently found it easier to learn words. They seemed to have developed an understanding of the principle of labelling in sign, which then transferred to the spoken word. This effect has been demonstrated mainly in conditions of structured teaching, and it is not known whether the same kind of’ generalisation would occur without highly systematic teaching of associations. Most researchers suggest (eg Kiernan 19832) that it is not enough to rely on the spontaneous transfer of signing to speech. However, there is some evidence of the spontaneous emergence of speech. For example, in a single case study by von Tetzchner 1984, a language disordered child improved his speech skills
