LEXICAL DEVELOPMENT DURING MIDDLE INFANCY - A MUTUALLY DRIVEN INFANT-CAREGIVER PROCESS

Individual differences in mothers' tendencies to describe aspects of the environment occupying their infants' current focus of attention were measured during interactions with their 13-month-old infants. The frequency of these current maternal utterances was then correlated with measures of their infants' productive lexical development at 13 and 24 months of age. In 19 dyads in which mothers had been employed outside of the home during their infant's first 2 years, the correlations between the maternal input measure and infant lexical development were significantly lower than those observed in 19 dyads in which the mothers were at home as full-time caregivers during this period of development. The dissociation of this relationship in dyads with mothers employed outside of the home suggests that early maternal input accounts for some of the variance in subsequent infant lexical development.