Data from 226 adoptive and 224 nonadoptive families was used to explore the etiology of individual differences in communication development. Children's scores from the Sequenced Inventory of Communication Development (SICD) were compared with verbal and cognitive ability measures of their parents. Sibling correlations were also examined. (SKC)

Imitation by infants functions in two ways: (1) to help the individual understand a puzzling event, and (2) to indicate mutuality with another person. Although changes in cognitive understanding influence the course of imitation, the occurrence of imitation in specific situations may be governed by the interplay of the two functions that imitation…

Examined the development of communicative competence in deaf children and its interactions with use of communicative gestures and/or words. Data indicated (1) the use of communicative gestures increased with age while speech remained constant; and (2) the number of gestures used correlated with communicative accuracy. Difficulty level influenced…