Like every other step in the 9-month process, the initiation of labor involves a complex interplay of maternal and fetal factors mediated through chemical signals. The growing fetus has been sustained by the maternal heart/lung/immune/nutrition support system. And then, suddenly and dramatically, all of the infant’s developing systems must perform on their own at birth. The newborn is now thrust into physiological independence—but not without plenty of support.

When babies pass through the birth canal, they are inoculated with their mother’s vaginal bacteria. The bacteria they encounter are benign, thanks to a hormonal shift that has lowered the vaginal pH and allowed harmless bacteria to flourish. These bacteria quickly colonize the newborn’s gastrointestinal tract and in the process crowd out pathogenic varieties. The beneficial bacteria also support digestion, synthesize certain vitamins, and contribute to the development of the infant’s immune system.

Birth has a cultural component, too. Among the welcoming customs around the world that have developed to greet newborns, writes Sarah Blaffer Hrdy in Mother Nature, are these: “Bisayan women cleanse them with coconut oil and dust newborns with powder; Mixtecans grease them with almond oil; Marshelles with pure coconut oil; the ancient Greeks with olive oil; the Tewa bathe and then rub babies with cornmeal; the Caraja apply red dye; the Tiwi of North Australia cover neonates in charcoal; [the Khoikhoi] rub newborns all over with moist cow dung, followed by the juice of a fig tree, then smear them with sheep fat and finally dust them with fine powder.”

Hrdy draws special attention, however, to a practice that is shared by many traditional cultures and which she believes has deep evolutionary origins and profound consequences. And that, perhaps surprisingly, is the practice of passing babies around and letting others (referred to by anthropologists as “alloparents”) pitch in as caregivers. This is in sharp contrast to primates such as orangutans, chimpanzees, and gorillas, whose babies are initially inseparable from their mothers and stay pretty much glued to their mothers day and night.

That doesn’t mean that human mothers are less devoted to their offspring or are somehow cutting corners as parents. Hrdy concludes that this level of cooperation in baby care has been, in fact, one of the key drivers of human intellectual and social evolution. And from an evolutionary perspective, it makes sense. Carrying babies in a hunter-gatherer society was hard work; in terms of calories consumed, it may have been more costly than lactation itself, which requires about 500 calories per day. Sharing such a precious load involved many considerations, which, in turn, had major repercussions. A study of one particularly cooperative group, the Efe, from the Ituri rainforest in the African Congo, says Hrdy, found that “Efe babies average 14 different caretakers in the first days of life.” The power of this social cooperation is such, Hrdy believes, that “without alloparents, there never would have been a human species.”

Crying
Less speculative and far more familiar to parents outside hunter-gatherer societies is the fact of crying. “Birth launches the newborn into a totally new world,” writes developmental psychologist Claire Kopp in Baby Steps, a guide to infant and toddler development. “A newborn’s physiological disorientation is akin to what we would experience if we were suddenly propelled to outer space. When the umbilical cord is cut, the newborn begins his solo flight. The baby has to keep his plane aloft even though not all of his vital processes were checked out before liftoff and even though he has not been schooled about what to do if something malfunctions.”

Fortunately, babies have plenty of resources in their survival kits, including physical reflexes and their senses. One of the very important, and for parents, obvious, tools the infant has is crying. All mammal babies cry (though we often refer to nonhuman vocalizations as distress calls). It is a powerful mode of communication. Loud and conspicuous, crying is also a bit risky for an animal in the wild. Working in the animal baby’s favor, however, is the fact that the baby’s mother is usually in a better position to hear and respond to the call than are the predators that might be lurking around.

Though roaming saber-toothed cats are no longer part of the crying equation for human babies, the behavior has been hardwired by evolution into infants. “Crying is about the only way that babies have of telling us that something is not right,” explains Kopp. “Some of early crying is a result of overstimulation because babies don’t have any way to disengage from that. The other reason that infants cry is because of physiological upsets as opposed to psychological upsets.” That is, she might be hungry or cold, or have the hiccups or a tummy ache. “As far as we know, babies of this age are unaware of feeling the psychological states of boredom, anger, or fearfulness, no matter how much we tend to associate crying with sorrow and distress.”

While there are babies who seem to cry all the time and babies who seem to never make a peep, explains Kopp, there are general developmental trends in crying. Typically, very young babies might fret or cry an hour or so a day. This usually increases to about 2 hours at about 6-8 weeks of age, but by 3 months decreases back to an hour a day. At the same time, notes Kopp, “crying becomes less tied to upsets due to physiological distress or stimulus overload and is progressively more related to psychological needs.”

By 6 months, a baby’s crying has become even more sophisticated. At this point, says Kopp, “babies tend to coordinate their cries with looking toward a parent as if saying, ‘I need you,’” which of course they do. “Learning to understand the baby’s cry is a little like learning a new language,” advises Kopp. “Within a short time, most parents become skilled interpreters of cries.”

More on this topic

Mother-Baby Bond: The Biology of Love (VIDEO)
Mother-Baby Bond: The Biology of Love
Establishing New Life
Nurture & Protect
Growth & Sensations
Adapting & Anticipating
Joyous Mom, Joyous Baby
Your Baby Enters the World
Nourishing Body & Bond
Mother & Teacher
Nurturing Development
A Mutual Gaze
From Bump to Bundle

Related Health Centers:

Infant Nutrition Health Center, Mother-Baby Bond Health Center, Mother’s Milk Health Center, Monthly Infant Development Calendar Health Center,Weekly Pregnancy Calendar Health Center