The Case for Baby-wearing

Baby-wearing, or the practice of using wraps, slings, carriers, or other devices to hold a child onto a caregiver during daily activities, has become increasingly popular in Western cultures. Many mothers and fathers see this as an exercise in convenience and bonding, allowing for hands free cuddling with their child, from infancy into toddlerhood. There is a great deal of anecdotal and data based evidence that indicates children who are worn are less likely to cry, sleep better at night, and learn more about their environment as compared to babies who spend the majority of their time in bassinets, strollers, swings, etc. Until recently, however, there has been little exploration into why babies who are worn seem to cry less.

An article published this month in Current Biology by Gianluca Esposito and others tackles this very question. Their approach was two-fold. First, they carefully watched the crying, heartrate, and overall movement of infants left to lie in a crib, held by the mother seated in a chair, or held by a walking and moving mother. In all cases, heart rate decreased, movement slowed, and crying halted in the babies carried by a walking mother as opposed to babies held by a stationary mother or babies left to lie in their cribs. This can be interpreted to mean the 'carrying' of infants has a significant calming effect.

 This first experiment establishes that carrying an infant is calming, but any parent knows that. The second experiment delved into the 'why' of it all. The researchers surmised that infant carrying in human mothers was similar to mice carrying their pups by mouth. Lo and behold, baby mice who are carried also show the same characteristics as carried infants - decreased movement, vocalization, and heartrate. The researchers noted that the important cues to inducing this type of response were related to maternal-like touch (i.e. holding near the body in infants or holding by the scruff in mice) AND the sensation of movement. The other senses (maternal smell, sight of mother or moving surrounds, hearing cues) seemed to matter very little to this response. Further, this whole process seems to be governed by the 'parasympathetic nervous system' (the part of the nervous system associated with resting, digesting, and non "fight or flight" responses).Finally, they found that uncooperative pups (baby mice that would not calmed down when carried) made carrying too difficult for the mother, and she refused to carry them. This may have important implications into the evolutionary purpose of this response. A mother is better able to carry a compliant child, so the child's nervous system slows down, almost like a reflex, to allow for easy carrying, something that would have been helpful to avoid predators, move to new locations, or locate food.

In short, baby-wearing allows a parent to carry a child more often, and a carried child is a calm child. Its not just speculation, its SCIENCE!

(Gianluca Esposito, Sachine Yoshida, Ryuko Ohnishi, Yousuke Tsuneoka, Maria del Carmen Rostagno, Susumu Yokota, Shota Okabe, Kazusaku Kamiya, Mikio Hoshino, Masaki Shimizu, Paola Venuti, Takefumi Kikusui, Tadafumi Kato, Kumi O. Kuroda, Infant Calming Responses during Maternal Carrying in Humans and Mice, Current Biology, Available online 18 April 2013, ISSN 0960-9822, 10.1016/j.cub.2013.03.041. (http://www.sciencedirect.com/science/article/pii/S0960982213003436))