Maternal responsibility at 9- and 15-months and subsequent language outcomes in a sample of Italian-Canadian mother-child dyads

This study investigated mothers' responsivity to their 9- and 15-month-old infants. Maternal responsivity was defined as acknowledgment of the infants' vocalizations and gestures. Specifically, this research analyzed mothers' verbal, nonverbal, combined verbal and nonverbal responsivity, or lack of it, to infant vocalizations, gestures, and vocalization-gesture combinations. Mothers belonged to three educational levels, namely high school, community college, and university and ranged from 25--38 years of age at the time of the first home visit. Mother-infant dyads were videotaped in their homes for 15 minutes of naturalistic, unstructured interaction on three occasions between 9 and 15 months. Infant and child outcome measures were collected, including a measure of cognitive development at 10 months, 15-month vocabulary size, as well as expressive language and receptive vocabulary at 3 years. Results indicated developmental changes in infant communications as well as changes over time in mothers' 'sensitivity', when this was examined within specific modalities. The results of multiple regression analyses indicated that maternal variables, and in one case an infant variable, were related to subsequent cognitive and language outcomes. In particular, maternal use of verbal Acknowledgment, Imitation, Labels, and Object Manipulation gestures at 9 months predicted infant cognitive development at 10 months. Similarly, infant cognitive development at 10 months in addition to Maternal Sensitive Language and Imitation at 15 months predicted 15-month vocabulary size. Furthermore, Maternal Sensitive Language at 9 months in addition to Nonresponsivity and Tactile/Vestibular gestures at 15 months predicted 3-year receptive vocabulary. Finally, Total Responsivity at 9 and 15 months predicted 3-year expressive language. With respect to responsivity, female infants of college-educated mothers received the least responsive interaction at 9 months. However, these mothers provided the highest proportion of responsivity at 15 months. Results are discussed in terms of maternal beliefs regarding infant abilities and their role in subsequent development.