When a mother cuddles an infant, she affects the formation of neural connections. When a father hums a lullaby, the infant's brain responds by retaining the cells that feel the pleasure of the sound. Touching, comforting, rocking, talking, and singing to babies provide exactly what they need to stimulate their growing brains. As the baby is exposed to her unique surroundings, a remarkable thing happens. The brain activity resulting from environmental influences causes synaptic connections—neuron to neuron—to get stronger. The next time she's exposed to a similar influence, her brain cells respond more quickly and strongly. Meanwhile, those connections that aren't needed fall away. This use-it-or-lose-it model is the basis for each infant's growing individuality.
THE NEWBORN IS PREPARED
With a brain only about one-fourth ready, babies land right smack in the middle of a chaotic and messy real world. The soothing things the growing fetus had in the womb—the peace to sleep, a controlled space for exploring her own movements, the comforting external movements of her mother, the familiar muffled sounds of the household—have been abruptly snatched away. Parents and caregivers help with the transition by paying close attention to comfort. But modern science tells us that, even though the world is confusing to newborns, they've got amazing devices with which to begin sorting it all out, right from the very start.
Despite the newborn's extreme immaturity, he is well prepared. He has at his disposal an arsenal of tools for himself; and some he'll find himself using in response to signals from mother, father, or caregivers.
Survival for an infant in the fourth trimester means being constantly close to a nurturing caregiver—to the soothing touch, sound, odor, and radiated warmth provided by someone who loves and pays close attention. Newborns are naturally built and equipped by evolution to prefer their mothers, though adopted infants have proven that their allegiance changes when it must. That closeness is a vital part of the transition from womb to world. Human babies pick up on movement patterns, breathing sounds, and body heat, all of which begin to regulate hormonal releases—melatonin to help manage the sleep-wake cycle and body temperature, and cortisol to regulate blood pressure, blood sugar, and immune response.
The kinds of behaviors that come naturally to parents and caregivers around the world are just what the baby needs. Rubbing and massaging her back, stomach, or legs keeps the infant warm; stimulates respiration, digestion, and elimination; and calms her down. Mothers naturally hold their babies most often on the left side of their bodies, and babies love feeling the soothing heartbeat. Mothers, fathers, and almost all adults talk in high-pitched voices when they speak to babies, and they look their babies in the eye. They've been doing these things for millions of years—exactly the things that newborns crave.
Just as the colt is born ready to stand, a human baby is born ready to recognize another human face, the smell of her mother's milk, and the familiar sound of her voice. It's precisely because human babies are so extremely neurologically immature at birth that they are exquisitely responsive to the body cues of adults, even to the point of matching the rhythm of breathing when they rest on a person's chest. Fetal life has prepared the newborn to recognize these cues from another loving body, and the familiarity helps to ease the transition of the fourth trimester. Babies have been responding to those instinctive touches, smells, and sounds since the first human put one foot in front of the other.
“We are all preemies at birth, relative to other primates. The baby is highly sensitized to gases the mother gives off,” says Dr. James McKenna, anthropologist and director of the Mother-Baby Behavioral Sleep Laboratory at the University of Notre Dame. “Every baby in the world—put them next to their mothers and they all do the same thing. They root. They breathe differently. The baby is waiting to respond to these kinds of things. They have come off a long evolutionary tree, and they know what to do.”13
Evolution, biology, genetics, and the environment all help to fashion one special baby, far better than anything parents might have imagined. But the deep well of parental love won't be returned in kind. Not yet. Babies need that love, can't thrive without it; but at first, it's all an infant can do to handle the new work of eating, breathing, and regulating her own heartbeat and digestion. She's not yet ready to show any signs of returning the outpouring of love. It can seem like unrequited love, but the demands and frustrations of the first months do not represent a failure of parenting. It's not personal. It's simply biology. Parents have waited for a baby, and they've been handed a mysterious, not-fully-formed neonate. Patience. The baby's brain, from the moment of birth, is beginning to mature, to figure out sleeping, seeing, hearing. It's part of the dance of life—her cries, grimaces, and involuntary smiles encouraging a parental response and paving the way for a two-way attachment.14 In time, she'll begin to respond. And one day soon, she'll smile, a reward making it all worthwhile.
WHETHER THEY KNOW IT OR NOT, PARENTS ARE PREPARED
Sometimes we describe newborns as “half-baked” or “almost finished.” In many ways this is true. Fortunately, nature, evolution, and three trimesters in the womb have prepared your newborn to begin the transition to the real world during the first three months outside the uterus. In these pages, readers will come to understand the fascinating and rapidly unfolding body of research from biologists, neuroscientists, developmental scientists, evolutionary anthropologists, and physicians that both explains why this new human being is so unformed and lays out what he needs during the fourth trimester. Parents, caregivers, and health care workers will gain confidence in knowing that, just as infants are equipped—with massive help from adults—to handle the transition to life outside the womb, these adults, too, are naturally prepared to provide exactly what babies need.
Armed with knowledge of the natural workings of infants, parents will be able to sort through the advice and opinions of friends, family, physicians, and a $10-billion-baby-product-marketing industry that tries to convince people that their products will make babies happier, calmer, and most assuredly, smarter.
This is not to say the work of the fourth trimester is easy. It isn't. Babies clearly are not trouble-free. Indeed, there will be twenty-four-hour demands, and nights that feel like endless struggles. But with an understanding of infants’ needs, limitations, and development during the fourth trimester, new mothers and fathers can begin their steady march down the parenting path with a maximum amount of self-assurance and a minimum amount of fear. As an understanding of one's mysterious newborn grows, so will the confidence needed to make the hundreds of daily decisions that will influence her growth and development.
Each healthy newborn is ready to begin this fascinating journey And each loving parent and caregiver, too, has what it takes to confidently provide everything a baby needs.
CHAPTER TWO
Crying
The Wakeup Call That Says Everything Has Changed
“I have never hurt him and don't believe I will, but I have had to leave the room he was in, go somewhere else and just breathe for a while, clenching and unclenching my fists,” author Anne Lamott writes of her son's crying.1
When a baby screws up his face, squeezes his eyes shut, and throws his head back for a full-throttled wail, it's normal. Healthy newborns cry an average of one to three hours a day, though to any parent it seems like a lot more. Even a colicky baby, who cries more than three hours a day, will usually outgrow it in three to four months.
Small comfort.
The sound itself is so jarring, so unsettling, that it has qualified as torture, according to Dr. Jerome Groopman, author and chair of medicine at Harvard Medical School.2 Quoting British social anthropologist Sheila Kitzinger, he says in his New Yorker article: “The sound of a crying baby . . . is just about the most disturbing, demanding,