The association between observed non-verbal maternal responses at 12 months and later infant development at 18 months and IQ at 4 years: A longitudinal study

BackgroundAn infant's early environment has an important influence on their development. For example, the sensitivity and warmth of a mother's responses towards her infant is associated with the infant's later socio-emotional development. However, it is less clear whether maternal responses are associated with the infant's later cognitive development.MethodWe used data from a large UK cohort study to investigate the association between non-verbal maternal responses and later infant development and IQ. Maternal responses were rated at 12 months during an observed mother–infant interaction. Infant development was assessed using the Griffiths scales at 18 months and IQ at 4 years was assessed using the Wechsler Preschool and Primary Scale of Intelligence (WPPSI). Data on the infant's developmental level at 6 months (prior to the maternal response ratings) was also available. The complete case sample comprised 732 mother–infant pairs.ResultsThere was evidence for an association between positive maternal responses and infant development at 18 months. After adjusting for infant developmental level at 6 months and other confounders, we found a difference of 0.25 standard deviations (coef 2.0, 95% CI (0.8–3.2), p = 0.002) on the Griffiths scales between infant's whose mothers showed positive compared to neutral non-verbal responses at 12 months. However, an association between positive maternal responses and IQ at 4 years diminished following adjustment for maternal educational attainment.ConclusionThe results provide evidence that positive maternal responses are associated with improved development in infants at 18 months. However, the association between maternal response and IQ at 4 years may be explained by higher educational attainment in mothers who show positive responses. Future studies are needed to explore the influence of maternal responses on different aspects of infant development as well as the role of maternal factors such as education.

► Maternal responses may be important for later infant development.
► We assessed the impact of maternal responses in a large longitudinal study.
► Positive maternal responses were associated with improved infant development at 18 months.
► Maternal education explained the association between maternal responses and IQ at 4.