It turns out that as important as the skin-to-skin contact we have with our babies in their early years, is the way we hold them. Unrelated to handedness and widespread across cultures, mothers cradle their babies on the left side. Even chimps and gorillas favor the left arm hold. Why, you ask? Apparently, a few researchers have found that the left-cradling tendency promotes right hemisphere-to-right hemisphere communication between mother and child (Manning et al., 1997; Harris, Almergi, & Kirsch 2000).
The right hemisphere is not only deeply connected with the autonomic nervous system, but is also specialized in perception, the recall of spatial patterns of touch in nonverbal memory, and facilitates affective information necessary for normal brain maturation. What’s important to know about the right hemisphere is that as the dominant emotional processing center, it controls vital functions that enable human beings to maintain a homeostatic state to support both survival and help cope with stressors. Right hemispheric dominance in terms of facial recognition, emotional information processing, and limbic system homeostasis suggests that both emotional and social intelligence—intrinsic to the development of courage—are dependent on right hemisphere stimulation and maturation through secure attachment.
From the first moments that an infant is held, the holder is not only engaging the already on-line limbic system’s amygdalae (hence an infant’s early startle response); but right-to-right hemispheric communication also supports analysis of information conveyed directly from the body. That is to say, when an infant is experiencing discomfort, or some immunological response, his/her cues to us are best received and recognized through right-to-right hemispheric communication. Schore (1994) proposes that secure attachment relationships directly influence the development of right brain psychosocial–neuroendocrine–immune communications which, in turn, directly affect a child’s coping capacities. Think back to the first moments that you held your child, did you hold them with your left arm or your right?
Emotion is the linchpin that enables us to adapt psychologically, physiologically, and behaviorally to have the courage to meet the challenges in our lives.
The next time your daughter is playing with her dolls, if she does that kind of thing, check out how she holds her doll. Not your son, though, this appears to be a uniquely maternal instinct. 
Very interesting!I noticed when I adopted my son that I always held him on my left and at first I worried this was somehow unbalanced.I tried to mix it up and hold him on the right sometimes, but found it just inexplicably annoying so I gave up and stuck with the left.Nice to know what was going on.
Thanks Barbaloot for taking this time to share how you intuitively held and bonded with your son! Glad to know that you, too, found the research interesting and affirming.
Very interesting.I did not know that it mattered which side you held your baby.As I read and thought back to when she was a baby she did get cradled mostly on the left side and nursed mostly on my left.Also, now when I hold her for reading or when she lies with me in bed it is usually on my left side…weird.
Thanks Anonymous for your interesting comment. All the studies utilized for this study are cited in the sources section. I would be cautious to extrapolate conclusions about a potential spouse's ability to bond with a baby based on this behavioral observation; however, as left-side holding does HELP to promote bonding, it is a useful habit to pick up to support parent-child bonding. That said, if a mom is nursing, regardless of left-hand hold preference some right-hand hold will be necessary to help nourish her child. The reason that we found this study so interesting is that it shows how wise nature is in promoting secure attachment for the healthy survival of the species! That said, if maternity nurses, midwifes, and early development/intervention specialists could help parents develop such secure attachment-promoting behaviors as simply as adopting the left-hand hold, babies would be the happy beneficiaries of enhanced right-brain development and secure parent-childattachment. With regards to the "red flag" you speak of, in my experience as a child/family therapist, asking the important questions, like those provided in the great book "The Conscious Bride," about marriage, having children, and child-rearing beliefs/values prior to marrying seems a more reliable gauge–but observing one another around children no doubt does provide interesting opportunities to observe our potential spouse as a possible future parent.
Many years ago my wife did volunteer work at a women's bureau.One of the things she was trained to do with new mothers is to watch which side they hold their child on.If they held their child on the right side, it was considered a possible warning sign that she wasn't bonding well with her child.I have since then not been able to find anything to support this. I have two questions.First, what studies, if any, support that?Second, we have seen one instance where a woman who didn't have any children yet held our children on her right side.We wondered if it wasn't a possible red flag that she may not be as excited about having children as the claimed she was because she almost always held our children on her right side. Sure enough when she got married, she is having problems bonding with her own child and sometimes seems annoyed by having to take care of him. If a young man is trying to determine whether or not he wants to marry a woman, and she consistently holds other people's children on her right side, should he consider that to be a possible red flag?