Men and Women's Waking Patterns to Infant Crying: Preparenthood Differences Are Insufficient to Explain Uneven Sharing of Nighttime Care

Crying in infancy is an important emotional signal that elicits care from adults, and women are often assumed to be more sensitive and reactive to infant crying than men. In a series of studies, we tested whether preparenthood gender differences in sensitivity to infant cries are a potential driver of the unequal share of early parenting. In Study 1, we tested for differences in men and women's awakening to infant crying and alarms among nonparents in an overnight experiment (N = 142). We found that at the lowest sound volumes only, estimated at a sound pressure level of between 33 and 44 decibels, women were 14% more likely to wake than men to both infant crying and alarm sounds. There were no differences between women and men at louder sound volumes. In Study 2, we examined the nighttime caregiving patterns of first-time parents over a week using experience sampling to obtain reports from both fathers and mothers (N = 117). We found that mothers were, on average, three times more likely to check on or respond to their infants at night than fathers. In 23% of couples, there was some evidence for equal sharing. Finally, in a simulation study, we reconstructed the distribution of care that could emerge from the awakening differences observed in Study 1. We then compared these simulations to the empirical nighttime caregiving patterns reported by first-time parents in Study 2. Our simulation showed that the large difference between parents' nighttime caregiving was unlikely to emerge from the small preparenthood differences in awakening likelihood. We conclude that the greater maternal share of nighttime caregiving cannot plausibly be explained by inherent preparenthood differences in auditory reactivity or nocturnal waking behavior in men or women.