Consistent responses of human mothers to prelinguistic infants: The effectof prelinguistic repertoire size

The salience of infants' vocal and visual cues was examined to evaluate the efficacy of prelinguistic vocalizations to guide adult behavior. A videota pe, constructed of brief behavioral episodes from 3 infants with different- sized vocal repertoires, was played to 40 mothers of prelinguistic infants. Playback mothers' responses to the episodes were consistent, demonstrating that preverbal behavior elicits comparable reactions across unfamiliar rec eivers. The audio and video components of the infants' episodes were then r ecombined. As the vocal repertoire of the stimulus infants increased, chang es in the audio component more often led playback mothers to change respons es. Thus, playback mothers used vocalizations as cues as the infants' vocal repertoires became larger.