Carrying human (and mouse) babies reduces their crying and heart rate.

Esposito et al. present some really nice observations. They demonstrate for the first time that the infant calming response to maternal carrying is a coordinated set of central, motor, and cardiac regulations and is a conserved component of mammalian mother-infant interactions. You should watch the video.


-Maternal carrying reduces crying, body movement, and heart rate of infants
-In mice, a similar set of calming responses is observed during carrying
 -Mouse calming response requires proprioception and somatosensation
 -The calming responses in infants function to increase maternal carrying efficacy

Here we show a novel set of infant cooperative responses during maternal carrying. Infants under 6 months of age carried by a walking mother immediately stopped voluntary movement and crying and exhibited a rapid heart rate decrease, compared with holding by a sitting mother. Furthermore, we identified strikingly similar responses in mouse pups as defined by immobility and diminished ultrasonic vocalizations and heart rate. Using pharmacologic and genetic interventions in mouse pups, we identified the upstream and downstream neural systems regulating the calming response. Somatosensory and proprioceptive input signaling are required for induction, and parasympathetic and cerebellar functions mediate cardiac and motor output, respectively. The loss of the calming response hindered maternal rescue of the pups, suggesting a functional significance for the identified calming response.