The effect of sustained maternal responsivity on later vocabulary development in children with Fragile X Syndrome

Purpose The research question addressed was whether sustained maternal responsivity (a parent-child interaction style characterized by warmth, nurturance and stability as well as specific behaviors such as contingent positive responses to child initiations) was a significant variable predicting vocabulary development of children with FXS through age 9 years. Method Fifty-five mother-child dyads were followed longitudinally when children were between 2 and 10 years of age. Measures of maternal responsivity and child vocabulary were obtained at regular intervals starting at age 2.9 years. Sustained responsivity was indicated by the average responsivity measured over observations 2–5. Responsivity at the first time period, autism symptoms, and cognitive development were used as control variables. Results After controlling for development and autism symptoms, we found significant effects for sustained responsivity on receptive vocabulary, expressive vocabulary, and the rate of different words children produced through age 9. Conclusions Maternal responsivity, which is typically a variable of interest during early childhood, continues to be a significant variable, predicting vocabulary development through the middle childhood period. Thus, responsivity is a potential target for language interventions through this age period