Caregivers' Monitoring of Infant Faces at Home: Developmental Decrease in Face Looking, But Not in Face Seeing

Infant learning is supported by caregivers, who coordinate their behaviors with those of the infants. Infants’ faces serve as a significant source of information, helping caregivers infer infants’ mental states and respond to them contingently. Despite the role of caregivers’ face monitoring in structuring infant–caregiver interaction, our knowledge about how caregivers monitor infants’ faces in everyday life and how these practices change with infant development remains limited. This study presents findings on the developmental changes in caregivers monitoring of infants’ faces in a home environment. We conducted longitudinal observations of daily infant–caregiver interactions, following eight infants from 10 months to 15.5 months while asking caregivers to wear head-mounted eye trackers. Employing a modern face detection algorithm and Bayesian statistical modeling analyses, we investigated the developmental changes in the presence of infants’ faces in caregivers’ view and looking behavior towards infants’ faces. Our results revealed no overall developmental change in the proportion of infants’ faces in caregivers’ view. However, we found a decrease in the proportion of caregivers’ looking at infants’ faces in view while controlling for factors that could influence face looking behavior. The findings suggest that caregivers maintain visual access to infants’ faces throughout infant development but decrease their visual attention toward infants’ faces. Additional analyses showed that caregivers were likely to look at infants’ manual actions on objects when caregivers were not looking at infants’ faces in view. Furthermore, this tendency strengthened as the infants aged. Together, our findings indicate the dynamic nature of caregivers’ social attention over developmental time and suggest that the development of infants’ manual actions may drive changes in caregivers’ attention allocation.