Brain Rules for Baby (Updated and Expanded). John Medina
Читать онлайн книгу.
attuned to these perceptions of safety, though they may not look it. At first blush, babies seem mostly preoccupied with more mundane biological processes, like eating and pooping and spitting up on your shirt. This fooled a lot of researchers into believing that babies weren’t thinking about anything at all. Scientists coined the term “tabula rasa”—blank slate—to describe these “empty” creatures. They regarded infants as merely helpless helpings of cute, controllable, human potential.
Modern research reveals a radically different point of view. We now know that a baby’s greatest biological preoccupation involves the organ atop their necks. Infants come preloaded with lots of software in their neural hard drives, most of it having to do with learning. Want some startling examples?
In 1979, University of Washington psychologist Andy Meltzoff stuck out his tongue at a baby 42 minutes old, then sat back to see what happened. After some effort, the baby returned the favor, slowly rolling out his own tongue. Meltzoff stuck his tongue out again. The infant responded in kind. Meltzoff discovered that babies could imitate right from the start of their little lives (or, at least, 42 minutes from the start of their little lives). That’s an extraordinary finding. Imitation involves many sophisticated realizations for babies, from discovering that other people exist in the world to realizing that they have operating body parts, and the same ones as you. That’s not a blank slate. That’s an amazing, fully operational cognitive slate.
Capitalizing on this finding, Meltzoff designed a series of experiments revealing just how much babies are prewired to learn—and how sensitive they are to outside influences in pursuit of that goal. Meltzoff constructed a wooden box, covered by an orange plastic panel, into which he inserted a light. If he touched the panel, the light turned on.
What happened next is described in the book The Scientist in the Crib: “[Andy] would show babies a completely unexpected way to use a new object—he would touch his forehead to the top of a box, and it would light up. The babies watched in fascination, but they weren’t allowed to touch the box themselves.” Mom and baby would then leave the lab, probably wondering what they’d just experienced. But the experiment wasn’t over: “A week later, the babies came back to the lab. This time Andy just gave them the box, without doing anything to it himself. But the babies immediately touched their foreheads to the top of the box.”
The babies remembered! With only a single exposure to this event, eight out of 12 babies recalled it perfectly a week later. None of the 24 babies in the control group made the motion on their own.
Those are just two examples illustrating that infants come equipped with an amazing array of cognitive abilities—and are blessed with many intellectual gadgets capable of extending those abilities. They understand that size stays constant even when distance changes the appearance of size. They display velocity prediction. They understand the principle of common fate; for example, the reason the black lines on the basketball move when the ball bounces is because the lines are part of the basketball. Infants can discriminate human faces from nonhuman faces at birth and seem to prefer human ones. From an evolutionary perspective, this latter behavior represents a powerful safety feature. We will be preoccupied with faces most of our lives.
How did babies acquire all of this knowledge before being exposed to the planet? Nobody knows, but they have it, and they put it to good use with astonishing speed and insight. Babies create hypotheses, test them, and then relentlessly appraise their findings with the vigor of a seasoned scientist. This means infants are extraordinarily delightful, surprisingly aggressive learners. They pick up everything.
There’s a funny example of this. A pediatrician was taking her 3-year-old daughter to day care. The good doctor had left her stethoscope in the backseat and noticed that the little girl began playing with it, even inserting the ear pieces correctly. The pediatrician got excited: Her daughter was following in her footsteps! The little girl grabbed the bell of the stethoscope, then put it to her mouth and declared in a loud voice: “Welcome to McDonald’s. Can I take your order, please?”
Yes, your children are constantly observing you. They are profoundly influenced by what they record. And that can quickly turn from funny to serious, especially when mommy and daddy start fighting.
Limited time to establish perceptions of safety
If survival is the brain’s most important priority, safety is the most important expression of that priority. This is the lesson Harlow’s iron maidens teach us. Babies are completely at the mercy of the people who brought them into the world. This understanding has a behavioral blast radius in infants that obscures every other behavioral priority they have.
How do babies handle these concerns? By attempting to establish a productive relationship with the local power structures—you, in other words—as soon as possible. We call this attachment. During the attachment process, a baby’s brain intensely monitors the caregiving it receives. It is essentially asking such things as “Am I being touched? Am I being fed? Who is safe?” If the baby’s requirements are being fulfilled, the brain develops one way; if not, genetic instructions trigger it to develop in another way. It may be a bit disconcerting to realize, but infants have their parents’ behaviors in their sights virtually from the moment they come into this world. It is in their evolutionary best interests to do so, of course, which is another way of saying that they can’t help it. Babies have nowhere else to turn.
There’s a window of several years during which babies strive to create these bonds and establish perceptions of safety. If it doesn’t happen, they can suffer long-term emotional damage. In extreme cases, they can be scarred for life.
We know this because of a powerful and heartbreaking story from Communist Romania, discovered circa 1990 by Western reporters. In 1966, in an effort to boost the country’s low birth rate, the dictator Nicolae Ceausescu banned both contraception and abortion and taxed those who were childless after age 25—whether married, single, or infertile. As the birth rate rose, so did poverty and homelessness. Children were often simply abandoned. Ceausescu’s response was to create a gulag of state orphanages, with children warehoused by the thousands.
The orphanages soon were stripped of resources as Ceausescu began exporting most of Romania’s food and industry to repay the country’s crippling national debt. The scenes in these orphanages were shocking. Babies were seldom held or given deliberate sensory stimulation. Many were found tied to their beds, left alone for hours or days, with bottles of gruel propped haphazardly into their mouths. Many infants stared blankly into space. Indeed, you could walk into some of these hundred-bed orphanages and not hear a sound. Blankets were covered in urine, feces, and lice. The childhood mortality rate in these institutions was sickening, termed by some Westerners “pediatric Auschwitz.” Horrible as these conditions were, they created a real opportunity to investigate—and perhaps treat—large groups of severely traumatized children.
One remarkable study involved Canadian families who adopted some of these infants and raised them back home. As the adopted children matured, researchers could easily divide them into two groups. One group seemed remarkably stable. Social behavior, stress responses, grades, medical issues—all were indistinguishable from healthy Canadian controls. The other group seemed just as remarkably troubled. They had more eating problems, got sick more often, and exhibited increasingly aggressive antisocial behaviors. The independent variable? The age of adoption.
If the children were adopted before the fourth month of life, they acted like every other happy kid you know. If they were adopted after the eighth month of life, they acted like gang members. The inability to find safety through bonding, by a specific age in infancy, clearly caused immense stress to their systems. And that stress affected these children’s behavior years later. They may have been removed from the orphanages long ago, but they were never really free.
What stress does is kick into action our “fight or flight” responses. They really should just be called “flight,” though. The typical human stress response is devoted to a single goal: getting enough blood into your muscles to get you out of harm’s way. We generally lash out only when cornered. Even then, we usually engage in combat just long enough to escape. When threatened, the brain signals the release of two hormones, epinephrine (also known as adrenaline) and cortisol,