A within-person analysis of the links between infant temperament, parenting, and sleep during the first year of life.

The transactional model of sleep identifies interactions between multiple factors, including infant temperament, parenting, and context contribute to variability in infant sleep. Research has focused on between-person designs and subjective or short observation periods, limiting the ability to examine variability in infant sleep. The present study utilized between-person methodologies to examine how supportive parenting and three temperamental characteristics were related to variability (i.e., fluctuations in sleep over time) and inertia (i.e., day-to-day influence of sleep) to capture stability in within-person sleep outcomes. Participants included parents (N = 208) of 4- to 12-month-old infants who were recruited by emails to Nanit baby monitor users. Sleep metrics from the Nanit baby monitor were provided nightly for up to two weeks, including total sleep time (TST) and parent visits to crib (PVC) through autovideosomnography and computer vision techniques from the Nanit. Participants completed questionnaires assessing infant temperament and parenting quality. Using dynamic structural equation modeling, we found that infant negative emotionality was associated with more TST inertia and lower PVC inertia. Infant effortful control was associated with more PVC inertia and lower TST inertia. Supportive parenting was associated with lower TST inertia and higher PVC inertia. When caregivers were higher in supportive parenting, there was a positive association between infant negative emotionality and TST inertia. In support of the transaction model of infant sleep, the current findings integrate social factors into infant sleep and build on infant sleep literature by identifying within-person variability in sleep behaviors in relation to infant temperament traits and supportive parenting.