Brain Rules for Baby (John Medina)

It’s a question that bothers many evolutionary scientists: How come it takes so long to raise a human child? Aside from perhaps a whale or two, we have the longest childhood on the planet. Where did this decades-long sojourn come from, and why don’t other animals have to go through what we do? Just a couple of delightful things we human parents endure:

Yes, you have to teach children everything—even how to regulate their body fluids. And they are built to learn, which means you have to watch even your most cavalier behaviors. Both take a tremendous amount of energy. So evolutionary biologists have to wonder: Why would anyone willingly take on this line of work? The interview for the job, that single act of sex, is certainly fun. But then you get hired to raise a child. There are wonderful moments, but the essence of the contract is simply: They take. You give. You never get a paycheck with this job, only an invoice, and you’d better be prepared for some sticker shock. You’ll be out more than $220,000—before the college loans. This career comes with no sick days or vacation time, and it puts you permanently on call nights and weekends. Its successful execution will probably turn you into a lifelong worrywart. Yet thousands of people every day say yes to this job. There must be some compelling reason.

But why does it take so much time and effort? Blame our big, fat, gold-plated, nothing-else-like-it brains. We evolved to have larger brains with higher IQs, which allowed us to move from leopard food to Masters of the Universe in 10 million very short years. We gained big brains through the energy savings of walking on two legs instead of four. But attaining the balance necessary to walk upright required the narrowing of the Homo sapiens pelvic canal. For females, that meant one thing: excruciatingly painful, often fatal births. An arms race quickly developed, evolutionary biologists theorized, between the width of the birth canal and the size of the brain. If the baby’s head were too small, the baby would die (without extraordinary and immediate medical intervention, premature infants wouldn’t last five minutes). If the baby’s head were too big, the mother would die. The solution? Give birth to babies before their skulls become too big to kill mom. The consequence? Kids come into the world before their brains are fully developed. The result? Parenthood. Because the bun is forced to come out of the oven before it is done, the child needs instruction from veteran brains for years. The relatives are the ones who get the job, as they brought the child into the world in the first place. You don’t have to dig deep into the Darwinian playbook to find a cogent explanation for parenting behavior. That’s not the entire mystery of parenting, but it underscores its importance. We survived because enough of us became parents good enough to shepherd our pooping, peeing, swearing, breathtakingly vulnerable offspring into adulthood. And we have no real say in the matter. A baby’s brain simply isn’t ready to survive the world. Clearly, childhood is a vulnerable time. More than a decade passes between the birth of a baby and its ability to reproduce—an eternity compared with other species. This gap shows not only the depth of the brain’s developmental immaturity but also the evolutionary need for unflinchingly attentive parenting. As we evolved, adults who formed protective and continuous teaching relationships with the next generation were at a distinct advantage over those who either could not or would not. In fact, some evolutionary theorists believe that language developed in all its richness just so that this instruction between parent and child could occur with greater depth and efficiency. Relationships among adults were crucial to our survival as well—and they still are, despite ourselves.

It’s vital that this neural tube develop properly. If it doesn’t, the baby could have a protruding spinal cord or a tumor near his lower back, a condition known as spina bifida. Or the baby could grow without a complete head, a rare condition known as anencephaly. This is why every pregnancy book strongly recommends taking the B-complex vitamin folic acid: It helps shape the proper neural tube—both the near and far ends. Women who take folic acid around conception and during the first few weeks of pregnancy are 76 percent less likely to create a fetus with neural tube defects than those who don’t take the supplement. It is the first thing you can do to aid brain development.

Fortunately, most babies’ brains form just fine. The brain end of the neural tube continues its construction project by creating bulges of cells that look like complex coral formations. These eventually form the large structures of the brain. Before the first month, the baby’s tiny pre-brain cell has grown into a hefty army, millions of cells strong. The brain does not develop in isolation, of course. The early embryo temporarily displays gill arches around the fourth week, for example, much like the ones fish have. These soon convert into face muscles and the throat structures that will allow your baby to speak. Your embryo next gets the stub of a tail but soon reverses course and resorbs the structure. There are strong evolutionary roots to our development, and we share this miracle with every other mammal on the planet. Except for one thing.

Cell migration reminds me of when tracking bloodhounds are suddenly loosed from the sheriff’s truck to pick up the scent of a criminal. Neurons bolt out of their ectodermal cages, crawling over one another, sniffing out molecular cues, pausing, trying out different pathways, slithering helter-skelter throughout the developing brain.

So the questions for prying parents become: What do fetuses know, and when do they know it? When is your baby capable of sensing, say, taps on your belly? The developmental principle to remember is this: The brain spends the first half of pregnancy setting up its neuroanatomical shop, blissfully ignoring most parental involvement. (I am referring to well-intentioned interference. Drugs, including alcohol and nicotine, clearly can damage a baby’s brain during pregnancy.) The second half of pregnancy is a different story. As brain development moves from mostly neurogenesis to mostly synaptogenesis, the fetus begins to exhibit much greater sensitivity to the outer world. The wiring of cells is much more subject to outside influences—including you—than the act of creating them in the first place.

There is hope. We know four of the most important sources of marital conflict in the transition to parenthood: sleep loss, social isolation, unequal workload, and depression. We will examine each. Couples who make themselves aware of these can become vigilant about their behavior, and they tend to do better. We also know that not every marriage follows this depressing course of events.

Harlow’s classic attachment experiments involved two of these iron maidens—doll-like structures serving as maternal stand-ins. One was made of harsh wire, the other of soft terry cloth. He took newly born rhesus monkeys, removed them from their biological mothers, and placed them into cages containing both dolls. There are many variations on this experiment, but the initial finding was striking. The cold wire doll provided food, delivered from an attached bottle. The soft terry-cloth doll did not. Nonetheless, the animals greatly preferred the cloth mom. The baby would feed from the wire mom, but do so while clinging tightly to the cloth mom. If the babies were placed in an unfamiliar room, they clung tightly to the cloth surrogate until they felt secure enough to explore the cage on their own. If placed in that same room without the cloth mother, the animals froze in terror, then went crying and screaming, running from one object to another, seemingly looking for their lost mother. The preference was the same no matter how many times the experiment was done or in what variation. These experiments are heartbreaking to watch—I’ve seen old films of this stuff—and the conclusions are unforgettable. It wasn’t the presence of food that telegraphed reassurance to these little ones, a behavioral idea prevalent at the time. It was the presence or absence of a safe harbor. Human babies, complex as they are, are looking for the same thing.

Babies are highly 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.

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.

Even in an emotionally stable home, one without regular marital hostility, there will be fights. Fortunately, research shows that the amount of fighting couples do in front of their children is less damaging than the lack of reconciliation the kids observe. Many couples will fight in front of their children but reconcile in private. This skews a child’s perceptions, even at early ages, for the child always sees the wounding but never the bandaging. Parents who practice bandaging each other after a fight, deliberately and explicitly, allow their children to model both how to fight fair and how to make up.

Why will you fight? I mentioned four consistent sources of marital conflict in the transition to parenthood. Left to their own devices, all can profoundly influence the course of your marriage, and that makes them capable of affecting your child’s developing brain. I’ll call them the Four Grapes of Wrath. They are:        •    sleep loss        •    social isolation        •    unequal workload        •    depression If you have a child, you are statistically likely to tramp on at least a few of these when your baby comes home. The battle begins in bed—and no, it’s not about sex.

Sleep-deprived people become irritable—far more irritable—than people who are not. Subjects saddled with sleep debt typically suffer a 91 percent loss in their ability to regulate strong emotions compared with controls. The decline in general cognitive skill is equally dramatic (which is why chronically drowsy people don’t perform as well at work, either). Problem-solving abilities typically plummet to 10 percent of their non-drowsy performances, and even motor skills become affected. You have to be moderately sleep deprived for only a week to start getting these numbers. Mood changes occur first; cognitive changes come next, followed by alterations in physical performance. If you don’t have a lot of energy, and you are called upon to give to your youngest several times a minute (preschoolers demand some form of attention 180 times per hour, behavioral psychologists say), you quickly exhaust your reservoir of good will toward your spouse. Sleep loss alone can predict most of the increases in hostile interactions between new parents.

Loneliness, painful and ubiquitous, is experienced by as many as 80 percent of new parents. After the birth of a child, couples have only about one-third as much time alone together as they had when they were childless. The thrill of having a child wears off, but the incessant job of parenting does not. Being a mom or dad becomes a duty, then a chore. Night after sleepless night depletes the family energy supply; increasing spousal conflicts exhaust the reserves. These losses cause a couple’s social activities to run out of gas. Mom and dad have trouble maintaining friendships with each other, let alone with acquaintances. Friends stop coming over. Parents find little energy to make new ones. Outside of their spouses, typical new parents have less than 90 minutes per day of contact time with another adult. A whopping 34 percent spend their entire days in isolation. Not surprisingly, many new parents feel trapped. Said one stay-at-home mother, “Some days, I just want to shut myself in my bedroom and talk on the phone with my best friend all day instead of dealing with my children. I love them, but being a stay-at-home mom is not all I dreamt it would be.” Another simply said of the loneliness: “I cry in my car. A lot.”

This may explain why, in the vast majority of cases, the increase in hostile interactions usually starts with the woman and spreads to the man.

What to make of the transition to parenthood? We have so far outlined an experience that requires a “giving response” three times per minute, allows half the sleep you need, provides little energy for friendships, and turns issues like who takes out the garbage into divorce risks. If these aren’t perfect conditions from which to ferment our final Grape of Wrath, I don’t know what are. Our fourth subject is depression. Fortunately, the majority of you won’t experience it, but it is serious enough to warrant attention. About half of all new mothers experience a transient postpartum sadness that vanishes within a few days. These baby blues are typical. But another 10 percent to 20 percent of mothers experience something much deeper and infinitely more troubling. These women are dogged by feelings of deepening despair, sorrow, and worthlessness, even if their marriages are doing well. Such painful, bewildering feelings last for weeks and months. Afflicted mothers cry all the time or simply stare out the window. They may stop eating. They may eat too much. These mothers are becoming clinically depressed, a condition known as postpartum depression.

Couples who know about the Four Grapes of Wrath and who begin preparing in advance are much less likely to trample on them once baby comes home. When conflicts occur for these couples, the effects are usually much milder. I can attest to that. I grew up in a military household in the 1950s. Whenever we took a car ride, my mother scrambled to prepare two kids under 3 years of age for the excursion, assembling blankets, bottles, diapers, and clean clothes. My father never assisted and actually grew impatient if preparations took too long. Storming out of the house, he would plunk down in the driver’s seat and gun the engine to announce his irritation. Lots of strong feelings there, about as useful as a heart attack. I only dimly recalled this behavior as an adult. But six months into my own marriage, my wife and I were late to a grad school meet-and-greet dinner. She was taking an especially long time to get ready, and I grew impatient. I stormed out of the house, got into the car, and put the key into the ignition. All of a sudden it hit me what I was doing. I remember taking a long breath, marveling at how deeply parents can still influence their kids, and then recalling novelist James Baldwin’s quote: “Children have never been good at listening to their parents, but they have never failed to imitate them.” Slowly, I removed the keys from the ignition, returned to my new bride, and apologized. I never pulled that stunt again. Years later, getting ready for a trip with two kids of our own, I was putting our youngest in the car seat when suddenly his diaper exploded. I grinned as I felt my car keys in my pocket and repaired to the changing table, humming. There would be no gunning of an engine. The lesson was long-lasting, the change surprisingly easy to maintain. There is nothing particularly heroic about this story. Nothing really changed except a specific awareness. But it is this awareness that I want to share, for its inner workings have very powerful positive consequences.

The story of the car keys involves a change in perspective, which I like to describe as “What is obvious to you is obvious to you.” My father did not see what needed to be done to get the kids ready (and may not have wanted to help even if he did). But my mother saw very clearly what needed to be done. There was a “perceptual asymmetry” in their points of view. It led to some really nasty fights. In 1972, sociologists Richard Nisbett and Edward Jones hypothesized that perceptual asymmetry lay at the heart of most conflicts. They further suggested that bridging this asymmetry would assist in most conflict resolutions. They were right. Their key observation was this: People view their own behaviors as originating from situations beyond their control, but they view other people’s behaviors as originating from inherent personality traits. Say a guy arrives late for a date. He is likely to ascribe his tardiness to external factors (being caught in traffic). She is likely to ascribe his tardiness to being a careless person (not taking traffic into account). One invokes a situational constraint to explain being late. The other invokes an insult. Nisbett and colleagues have been cataloguing these asymmetries for decades. Nisbett found that people tend to have inflated views of themselves and their futures. They think they’re more likely than they actually are to become wealthy and to have a brighter occupational future, and are somehow less likely to contract infectious diseases (one reason illnesses like cancer can be so emotionally devastating is that people never think it will happen to them, only to the “other guy”). People overestimate how much they can learn about others from short encounters. When fighting, people believe they are perfectly unbiased, informed, and objective, while simultaneously thinking their opponents are hopelessly prejudiced, clueless, and subjective.

These asymmetries originate from a phenomenon well established in the cognitive neurosciences. Any human behavior has many moving parts, roughly divisible into background and foreground elements. Background components involve our evolutionary history, genetic makeup, and fetal environment. Foreground components involve acute hormones, prior experiences, and immediate environmental triggers. Alone in our skulls, we have privileged access to both sets of components, providing detailed knowledge of our psychological interiors, motivations, and intentions. Formally called introspection, we know what we intend to mean or to communicate on a minute-to-minute basis. The problem is, nobody else does. Other people can’t read our minds. The only information others have about our interior states and our motives is what our words say and how our faces and bodies appear. This is formally called extrospection. We are amazingly blind to the limits of extrospective information. We know when our actions fail to match our inner thoughts and feelings, but we often forget that this knowledge is not available to others. The disparity can leave us bewildered or surprised at how we come across to other people. As poet Robert Burns wrote, “Oh that God the gift would give us / to see ourselves as others see us.” Introspective knowledge clashing with extrospective information is the Big Bang of most human conflicts. It has been directly observed between people trying to give directions to a lost soul and between warring nations trying to negotiate a peace agreement. It forms the basis of most breakdowns in communication, including conflicts in marriage.

Research shows that 70 percent of marital conflicts are not resolvable; the disagreement remains. As long as the participants learn to live with their differences—one of the biggest challenges in marriage—this is not necessarily bad news. But differences must be grasped, even if no problems are solved. One of the reasons empathy works so well is because it does not require a solution. It requires only understanding. That’s extremely important to recognize. If there is wiggle room for negotiation only 30 percent of the time, empathy becomes the premier exercise in any couple’s conflict-management workout. That’s probably why its absence is such a powerful predictor of divorce. Gottman, among other researchers, discovered a similar effect in child rearing. He has said, “Empathy not only matters; it is the foundation of effective parenting.”

For all of us, nature controls about 50 percent of our intellectual horsepower, and environment determines the rest. This means two things for parents: First, no matter how hard your child tries, there will be limits to what his brain can do. Second, that’s only half of the story. Aspects of your child’s intelligence will be deeply influenced by his environment, especially by what you do as parents. We’ll look at both the seed and the soil. This chapter discusses the biological basis of a child’s intelligence. The next chapter explains what you can do to optimize it.

What did they discover? The most surprising finding was that there was nothing surprising. Einstein had a fairly average brain. The organ had a standard internal architecture, with a few structural anomalies. The regions responsible for visuospatial cognition and math processing were a bit larger, 15 percent fatter than average. He was also missing some sections that less agile brains possess, accompanied with a few more glial cells than most people carry (glial cells help give the brain its structure and assist with information processing). None of these results are very instructive, unfortunately. Most brains possess structural abnormalities: some regions more shrunken than others, some more swollen. Because of this individuality, it is currently impossible to demonstrate that certain physical differences in brain structure lead to genius. Einstein’s brain certainly was smart, but not one of its dice-sized pieces would definitively tell us why.

When you examine living geniuses solving some tough problem, you do not find reassuring similarities; you find disconcerting individualities. Problem solving and sensory processing do not look the same in any two brains.

Like Kirstie’s dress size, IQ is malleable. IQ has been shown to vary over one’s life span, and it is surprisingly vulnerable to environmental influences. It can change if one is stressed, old, or living in a different culture from the testing majority. A child’s IQ is influenced by his or her family, too. Growing up in the same household tends to increase IQ similarities between siblings, for example. Poor people tend to have significantly lower IQs than rich people. And if you earn below a certain income level, economic factors will have a much greater influence on your child’s IQ than if your child is middle class. A child born in poverty but adopted into a middle-class family will on average gain 12 to 18 points in IQ. There are people who don’t want to believe IQ is so malleable. They think numbers like IQ and “g” are permanent, like a date of birth instead of a dress size. The media often cast our intellectual prowess in such permanent terms, and our own experience seems to agree. Some people are born smart, like Theodore Roosevelt, and some people are not. The assumption is reassuringly simplistic. But intelligence isn’t simple, and neither is our ability to measure it.

Harvard psychologist Howard Gardner, who published his latest theory of multiple intelligences in 1993, put it this way: Strong evidence exists “that the mind is a multifaceted, multicomponent instrument, which cannot in any legitimate way be captured in a single paper-and-pencil-style instrument.” Ready to cry uncle? Is intelligence going to be the province of comments like “I don’t know what it is, but I know when I see it”? No, but to see the issue more clearly, we are going to have to replace this one-number-fits-all notion. Human intelligence is more like ingredients in a stew than numbers in a spreadsheet.

Like Mom’s stew, human intelligence has two essential components, both fundamentally linked to our evolutionary need to survive. The first is the ability to record information. This is sometimes called “crystallized intelligence.” It involves the various memory systems of the brain, which combine to create a richly structured database. The second component is the capacity to adapt that information to unique situations. This involves the ability to improvise, based in part on the ability to recall and recombine specific parts of the database. This capacity for reasoning and problem solving is termed “fluid intelligence.” From an evolutionary perspective, the potent combination of memorization and extemporization conferred on us two survival-rich behaviors: the ability to learn rapidly from our mistakes and the ability to apply that learning in unique combinations to the ever-changing, ever-brutal world of our East African cradle. Intelligence, seen through this evolutionary lens, is simply the ability to do these activities better than someone else.

Many ingredients make up the human intelligence stew, and I’d like to describe five that I think you would do well to consider as you contemplate your child’s intellectual gifts. They are:        •    The desire to explore        •    Self-control        •    Creativity        •    Verbal communication        •    Interpreting nonverbal communication Most of these characteristics fall outside the spectrum of the usual IQ suspects. We believe many have genetic roots; most can be seen in newborns. Rooted as these five ingredients may be in our evolutionary history, however, they do not exist in isolation from the outside world. Nurture—even for Teddy Roosevelt—plays an important role in whether a child is able to maximize his or her intelligence.

What traits separate creative, visionary people who consistently conjure up financially successful ideas from less imaginative, managerial types who carry them out? Two business researchers explored that simple question. They conducted a whopping six-year study with more than 3,000 innovative executives, from chemists to software engineers. After being published in 2009, the study won an award from Harvard Business Review. Visionaries had in common five characteristics, which the researchers termed “Innovator’s DNA.” Here are the first three: •    An unusual ability to associate. They could see connections between concepts, problems, or questions not obvious to others. •    An annoying habit of consistently asking “what if.” And “why not” and “how come you’re doing it this way.” These visionaries scoured out the limits of the status quo, poking it, prodding it, shooting upward to the 40,000-foot view of something to see if it made any sense and then plummeting back to earth with suggestions. •    An unquenchable desire to tinker and experiment. The entrepreneurs might land on an idea, but their first inclination would be to tear it apart, even if it was self-generated. They displayed an incessant need to test things: to find the ceiling of things, the basement of things, the surface area, the tolerance, the perimeters of ideas—theirs, yours, mine, anybody’s. They were on a mission, and the mission was discovery. The biggest common denominator of these characteristics? A willingness to explore. The biggest enemy was the non-exploration-oriented system in which the innovators often found themselves. Hal Gregersen, one of the lead authors of the study, said in Harvard Business Review: “You can summarize all of the skills we’ve noted in one word: ‘inquisitiveness.’ I spent 20 years studying great global leaders, and that was the big common denominator.” He then went on to talk about children: “If you look at 4-year-olds, they are constantly asking questions. But by the time they are 6½ years old, they stop asking questions because they quickly learn that teachers value the right answers more than provocative questions. High-school students rarely show inquisitiveness. And by the time they’re grown up and are in corporate settings, they have already had the curiosity drummed out of them.

Welcome to the interesting world of impulse control. It is part of a suite of behaviors under the collective term “executive function.” Executive function controls planning, foresight, problem solving, and goal setting. It engages many parts of the brain, including a short-term form of memory called working memory. Mischel and his many colleagues discovered that a child’s executive function is a critical component of intellectual prowess. Executive function is a better predictor of academic success than IQ. We now know that it is actually a better predictor of academic success than IQ. It’s not a small difference, either: Mischel found that children who could delay gratification for 15 minutes scored 210 points higher on their SATs than children who lasted one minute. Why? Executive function relies on a child’s ability to filter out distracting (in this case, tempting) thoughts, which is critical in environments that are oversaturated with sensory stimuli and myriad on-demand choices. That’s our world, as you have undoubtedly noticed, and it will be your children’s, too. Once the brain has chosen relevant stimuli from a noisy pile of irrelevant choices, executive function allows the brain to stay on task and say no to unproductive distractions.

Can you predict creativity in kids? Psychologist Paul Torrance created a 90-minute exam called the Torrance Tests of Creative Thinking. The tests are composed of some truly delightful problems. Children might be presented with a picture of a stuffed rabbit, then told they have three minutes to improve upon the design to make it more fun to play with. They might be presented with a scribble, then told to make a narrative from it. Torrance first administered the exam in 1958 to several hundred children, then followed their lives into adulthood, assessing their creative output throughout: things like patents filed, books written, papers published, grants awarded, and businesses started. The study is still ongoing, the participants christened “Torrance’s Kids.” Torrance died in 2003, and the study is now supervised by colleagues. As a research tool, the exam has been formally evaluated many times. Though the test is not without its critics, the most amazing finding remains how well a child’s scores predict his or her future creative output. Indeed, the scores predict lifetime creative output with a correlation three times stronger than native IQ can predict. The test has been translated into 50 languages and taken by millions of people. It is the go-to standard for evaluating creativity in children.

What is strong enough, Kuhl and other researchers wondered, to keep that door from closing? Say you expose your baby, in the critical period, to a tape of someone speaking a foreign language. Does the brain stay open for phonemic business? The answer is no. How about a DVD of someone speaking the foreign language? The door continues to shut. Only one thing keeps that door open to another language. You have to deliver the words through a social interaction. A real live person has to come into the room and speak the language directly to the child. If the child’s brain detects this social interaction, its neurons will begin recording the second language, phonemes and all. To perform these cognitive tasks, the brain needs the information-rich, give-and-take stimulation that another human being provides. Tucked into these data is a bombshell of an idea, one with empirical support across the developmental sciences. Human learning in its most native state is primarily a relational exercise. Intelligence is not developed in the electronic crucibles of cold, lifeless machines but in the arms of warm, loving people. You can literally rewire a child’s brain through exposure to relationships.

Gestures and speech used similar neural circuits as they developed in our evolutionary history. University of Chicago psycholinguist David McNeill was the first to suggest this. He thought nonverbal and verbal skills might retain their strong ties even though they’ve diverged into separate behavioral spheres. He was right. Studies confirmed it with a puzzling finding: People who could no longer move their limbs after a brain injury also increasingly lost their ability to communicate verbally. Studies of babies showed the same direct association. We now know that infants do not gain a more sophisticated vocabulary until their fine-motor finger control improves. That’s a remarkable finding. Gestures are “windows into thought processes,” McNeill says.

Paul Ekman, professor emeritus from the University of California–San Francisco, seldom misinterprets people’s faces. He has cataloged more than 10,000 possible combinations of facial expressions, creating an inventory called the Facial Action Coding System (FACS). This research instrument allows a trained observer to dissect an expression in terms of all the muscular actions that produced it. Using this tool, Ekman has found several surprising things about human facial recognition. First, people all over the world express similar emotions using similar facial muscles. These universal basic emotions are happiness, sadness, surprise, disgust, anger, and fear. (The finding was originally quite startling; research at the time chalked up facial expressions mostly to cultural mores.) Second, the conscious control we can exert over our facial features is limited, which means we give away a lot of free information. The muscles that surround our eyes, for example, are not under conscious management. This may be why we tend to believe them more.

From exploration, self-control, and creativity to verbal and nonverbal ability, it is clear that the intelligence stew has many ingredients. Standard IQ tests are not capable of measuring most of these elements, even though they play a powerful role in the future success of your children. Given their uniqueness, that’s not surprising. Some are so unexpected as to defy belief (your kid’s chances of being a great entrepreneur are linked to her ability to decode faces?). So you need not be discouraged if your kid isn’t in the 97th percentile on certain tests. She may have many other intellectual aspects in abundance that IQ tests are inherently incapable of detecting. That’s not to say that everyone is a potential Einstein. These gifts are unevenly sprinkled among our children, and most have genetic components. Your autistic child may never have the warmth of a pastor, for example, no matter how hard you try. But as you know, there’s more to intelligence than just seeds.

Regardless of their genes, you can help your children mobilize their intelligence as fully as Theodore Roosevelt, Albert Einstein, or the most successful innovators working today. Just how do you grow a smart baby? We’re thinking in terms of soil, so it makes sense to formulate a fertilizer. What you put in is as important as what you leave out. There are four nutrients you will want in your behavioral formula, adjusting them as your baby gets older: breast-feeding, talking to your baby, guided play, and praising effort rather than accomplishment. Brain research tells us there are also several toxins: pushing your child to perform tasks his brain is not developmentally ready to take on; stressing your child to the point of a psychological state termed “learned helplessness”; and, for the under-2 set, television. A few additives, hawked by marketers, are optional to irrelevant. What we’ll discover is the profound need to strike a balance between intellectual freedom and well-disciplined rigor.

First, I need to correct a misconception. Many well-meaning moms and dads think their child’s brain is interested in learning. That is not accurate. The brain is not interested in learning. The brain is interested in surviving. Every ability in our intellectual tool kit was engineered to escape extinction. Learning exists only to serve the requirements of this primal goal. It is a happy coincidence that our intellectual tools can do double duty in the classroom, conferring on us the ability to create spreadsheets and speak French. But that’s not the brain’s day job. That is an incidental by-product of a much deeper force: the gnawing, clawing desire to live to the next day. We do not survive so that we can learn. We learn so that we can survive. This overarching goal predicts many things, and here’s the most important: If you want a well-educated child, you must create an environment of safety. When the brain’s safety needs are met, it will allow its neurons to moonlight in algebra classes. When safety needs are not met, algebra goes out the window.

Speak to your children as often as you can. It is one of the most well-established findings in all of the developmental literature. The linkage between words and smarts was discovered through some pretty invasive research. In one study, investigators descended upon a family’s home every month for three years and jotted down every aspect of verbal communication between parents and their children. They measured size of vocabulary, diversity and growth rate of vocabulary, frequency of verbal interaction, and the emotional content of the speech. Just before the visits were finished, the researchers gave IQ tests. They did this with more than 40 families, then followed up years later. Through exhaustive analysis of this amazingly tough work, two very clear findings emerged:        •    The variety and number of words matter.        •    Talking increases IQ. The more parents talk to their children, even in the earliest moments of life, the better their kids’ linguistic abilities become and the faster that improvement is achieved.

This kind of open-ended play was fertilizing their brains with the behavioral equivalent of Miracle-Gro. That sentence might seem strange. Open-ended play? Not “open-ended purchase of electronic educational toys”? Not French lessons, followed by hours of militant drilling? Actually, I do believe in a form of disciplined repetition as children begin formal schooling. But many parents are so preoccupied with their young child’s future that they transform every step of the journey into a type of product development, recoiling at open-ended anything. From 1981 to 1997, the amount of free time parents gave their kids shrank by about a quarter. In the Atlantic, Esther Entin details more of that same study: Children “spent 18 percent more time at school, 145 percent more time doing school work, and 168 percent more time shopping with parents. The researchers found that, including computer play, children in 1997 spent only about eleven hours per week at play.” Children’s free time hasn’t improved since then. Researcher Peter Gray noted in 2011 that the number has been declining for more than half a century. The making-baby-smart product industry—fashioning toys that are the opposite of open-ended (what could be more claustrophobic than a DVD for infants?)—is a multibillion-dollar industry. We now know that open-ended activities are as important to a child’s neural growth as protein.

the type of play that gives all the cognitive benefits is a type that focuses on impulse control and self-regulation—those executive-function behaviors discussed in the previous chapter as ingredients of intelligence, revealed by the cookie experiment. The data are so clear, you could use them to design the family playroom.

The type of play is called mature dramatic play, or MDP. To get the benefits in those bullet points, MDP has to be engaged in many hours a day. This has been codified into a school program called Tools of the Mind, one of the few programs of its type that has been studied in randomized trials. The ideas for Tools of the Mind come from Russian psychologist Lev Vygotsky, a handsome polymath who burned out quickly in the early years of the Soviet era.

Vygotsky was one of the few researchers of his era to study dramatic play in children. He predicted that the ability of the under-5 crowd to engage in imaginative activities was going to be a better gauge of academic success than any other activity—including quantitative and verbal competencies. The reason, Vygotsky believed, was that such engagement allowed children to learn how to regulate their social behaviors. Hardly the carefree activity we think of in the United States, Vygotsky saw imaginative play as one of the most tightly restrictive behaviors children experience. If little Sasha was going to be a chef, he would have to follow the rules, expectations, and limitations of “chefness.” If this imaginative exercise included friends, they would have to follow the rules, too. They might push and pull and argue with each other until they agreed on what those rules were and how they should be executed. That’s how self-control developed, he posited. In a group setting, such a task is extremely intellectually demanding, even for adults. If this sounds like a prelude to the more modern notion of executive function, you are right on the money. Vygotksy’s followers showed that children acting out imaginative scenes controlled their impulses much better than they did in non-MDP situations. While other parts of Vygotsky’s work are starting to show some intellectual arthritis, his ideas on self-regulation have held up well. The cascade of confirmatory research that followed these findings led directly to the Tools of the Mind program. It has a number of moving parts, but the three most relevant to our discussion involve planning play, direct instruction on pretending, and the type of environment in which the instruction takes place.

Most Tools of the Mind classrooms look like the equivalent of a late-Christmas-morning living room. Legos are scattered everywhere. Sandboxes are sprinkled around the room. There are jigsaw puzzles to figure out. Blocks with which to build entire new worlds. Clothes for dress-up. Places for crafts. Boxes! Lots of time—and space—for interaction with other kids. The combinations of situations in which individual imagination and creativity could be deployed are seemingly endless. Many other activities occur in the course of a Tools of the Mind day, and we don’t yet know which combinations work best. We also don’t know about the long-term effects of the program. As of this writing, no fewer than four long-term, large-scale studies are under way to answer these questions. But we do know this about the program: It works. Kids in the program typically perform 30 percent to 100 percent better than controls on just about any executive function test you throw at them. That means better grades, too, as high executive function is one of the two greatest predictors of academic success that exist in the research literature. And it means the many benefits we described earlier, most of which come from studies of the Tools program.

These data flatly state that emotional regulation—reining in impulses—predicts better cognitive performance. That’s a bombshell of an idea. It directly ties intellectual horsepower to emotional processing. I am not dismissing rote drills, as a memorized database is an extremely important part of human learning. But it is clear: Vygotsky was on to something.

What separates high performers from low performers is not some divine spark. It is, the most recent findings suggest, a much more boring—but ultimately more controllable—factor. All other things being equal, it is effort. Good old-fashioned neural elbow grease. Deliberate practice. From a psychological perspective, effort is in part the willingness to focus one’s attention and then sustain that focus. Effort also involves impulse control and a persistent ability to delay gratification. Sounds like executive function, spiced with a few unique ingredients.

How can you get that kind of effort from your child? Surprisingly, it’s how you praise him. What you praise defines what your child perceives success to be. Here is where parents make a common mistake—one that often creates the saddest sight a teacher can behold: a bright child who hates learning. Ethan’s parents constantly told him how brainy he was. “You’re so smart! You can do anything, Ethan. We are so proud of you,” they would say every time he sailed through a math test. Or a spelling test. Or any test. With the best of intentions, they consistently tethered Ethan’s accomplishment to some innate characteristic of his intellectual prowess. Researchers call this “appealing to fixed mindsets.” The parents had no idea that this form of praise was toxic. Little Ethan quickly learned that any academic achievement that required no effort was the behavior that defined his gift. When he hit junior high school, he ran into subjects that did require effort. He could no longer sail through, and, for the first time, he started making mistakes. But he did not see these errors as opportunities for improvement. After all, he was smart because he could mysteriously grasp things quickly. And if he could no longer grasp things quickly, what did that imply? That he was no longer smart. Since he didn’t know the ingredients making him successful, he didn’t know what to do when he failed. You don’t have to hit that brick wall very often before you get discouraged, then depressed. Quite simply, Ethan quit trying. His grades collapsed.

What should Ethan’s parents have done? Research reveals a simple solution. Rather than praising him for being smart, they should have praised him for working hard. On the successful completion of a test, they should not have said, “I’m so proud of you. You’re such a bright kid.” That appeals to a fixed, uncontrollable intellectual trait. It’s called “fixed mindset” praise. His parents should have said, “I’m so proud of you. You must have studied a lot.” This appeals to controllable effort. It’s called “growth mindset” praise. More than 30 years of study show that children raised in growth-mindset homes consistently outscore their fixed-mindset peers in academic achievement. They do better in adult life, too. That’s not surprising. Children with a growth mindset tend to have a refreshing attitude toward failure. Rather than seeing mistakes as failures over which to despair, they see mistakes simply as problems to be solved.

The second reason content is so important is that our expectations and assumptions profoundly influence our perception of reality. This is because of the brain’s eager willingness to insert its opinion directly into what you are currently experiencing—and then fool you into thinking this hybrid is the actual reality. It may disturb you to know this, but your perception of reality is not like a camcorder recording verbatim information to some cellular hard drive. Your perception of reality is a handshake agreement between what your senses bring to your brain and what your brain thinks ought to be there. And what you expect to be out there is directly tied to what you allowed into your brain in the first place. Experiences morph into expectations, which can, in turn, influence your behavior.

decades we have known of the connection between hostile peer interactions and the amount of kids’ exposure to television. The linkage used to be controversial (maybe aggressive people watch more TV than others?), but we now see that it’s an issue of our deferred-imitation abilities coupled with a loss of impulse control.

TV also poisons attention spans and the ability to focus, a classic hallmark of executive function. For each additional hour of TV watched by a child under the age of 3, the likelihood of an attentional problem by age 7 increased by about 10 percent. So a preschooler who watches three hours of TV per day is 30 percent more likely to have attentional problems than a child who watches no TV. Just having the TV on while no one is watching—secondhand exposure—seemed to do damage, too, possibly because of distraction. In test laboratories, flashing images and a booming sound track continually diverted children from any activity in which they were otherwise engaged, including that marvelous brain-boosting imaginative play we discussed. The effects were so toxic for kids in diapers that the American Association of Pediatrics issued a recommendation that still stands today: Pediatricians should urge parents to avoid television viewing for children under the age of 2 years. Although certain television programs may be promoted to this age group, research on early brain development shows that babies and toddlers have a critical need for direct interactions with parents and other significant caregivers (e.g., child care providers) for healthy brain growth and the development of appropriate social, emotional, and cognitive skills. Current research projects are addressing the potential effect of TV on grades, and preliminary work suggests that it affects both reading scores and language acquisition. But after age 2, the worst effects on kids’ brains may come because television coaxes kids away from exercise, a subject we will examine when we get to video games.

What does that literature say about video games and developing brains in babies? There’s not much, and it paints a decidedly mixed picture. This is understandable. The subject is too new, and the technology undergirding it is changing too rapidly. So what parents of newborns and toddlers should know about gaming comes not from data about what video games do to the mind but from what video games do to the body. As with television, most video games are consumed in a sedentary position: You sit there. Movement-oriented game consoles such as the Wii, which debuted in 2006, potentially provide an exception, but they seem to have made little dent: Kids’ weight is still rising precipitously. So pronounced is this weight-gain trend that our children are starting to get diseases usually associated with middle and later life—including arthritis! Childhood obesity is three times more prevalent in gamers than in non-gamers.

This rise in pediatric obesity is painful to hear in the brain science community, especially because we know so much about the relationship between physical activity and mental acuity. Exercise—especially aerobic exercise—is fantastic for the brain, increasing executive function scores anywhere from 50 percent to 100 percent. This is true across the life span, from young children to members of the golden-parachute crowd. Strengthening exercises, though there are many other reasons to do them, do not give you these numbers. Parents who start their kids out on a vigorous exercise schedule are more likely to have children for whom exercise becomes a steady, even lifelong, habit—up to 1½ times more likely, depending upon the study. Fit kids score higher on executive function tests than sedentary controls, and those scores remain as long as the exercise does. The best results accrue, by the way, if you do the exercises with your children. Remember that deferred-imitation business? Encouraging an active lifestyle is one of the best gifts you can give your child.

The brain appears to go through some commonly experienced developmental stages. But few in the brain science community completely agree on what they are. Developmental psychologist Jean Piaget (who worked for a time with Alfred Binet, the IQ guy) came up with four phases of cognitive development in kids, which he called sensorimotor, preoperational, concrete operational, and formal operational. Widely influential then, the concept of developmental stages is a contentious idea now. Researchers began to question the notion in the late 20th century when they showed that children acquire skills and concepts at much earlier stages than Piaget posited. Follow-up work revealed that, even within a given category, children go through developmental stages at their own pace. Many don’t follow the order Piaget conceived; they sometimes skip a step or two or repeat the same stage several times in a row. Some go through no definable stages at all. There is nothing wrong with our children’s brains. There is just something wrong with our theories. Some parents, though, think brain development is like running an Olympic race. They want their child to win at every step, whatever the cost. You can still see the effect of this mindset when these parents’ children get into college. Though I mostly teach graduate students, I occasionally instruct undergraduates who want to get into medical school, and they care about little else. Many describe being hot-housed by pushy parents who seem to see their kids more as merit badges than as people. This is called hyper-parenting, and it has been studied.

Write this across your heart before your child comes into the world: Parenting is not a race. Kids are not proxies for adult success. Competition can be inspiring, but brands of it can wire your child’s brain in a toxic way. Comparing your kids with your friends’ kids will not get them, or you, where you want to go. You can maximize your child’s brain power in plenty of wonderful ways. After breast-feeding, focus on open-ended play, lots of verbal interaction, and praising effort—fertilizers statistically guaranteed to boost your child’s intellect from almost any starting point. These things aren’t fancy. After all, the brain’s intellectual performance envelope was forged in a world that was not only pre-Internet but pre–Ice Age.

One researcher who has spent many years trying to get at the answer is a delightful elf of a psychologist named Daniel Gilbert, at Harvard. Other definitions of happiness exist, of course, but Gilbert proposes these three: •    Emotional happiness. This is what most of the parents I ask probably mean. This type of happiness is, Gilbert wrote, “a feeling, an experience, a subjective state” untethered to something objective in the real world. Your child is delighted by the color blue, moved by a movie, thrilled by the Grand Canyon, satisfied by a glass of milk. •    Moral happiness. Intertwined with virtue, moral happiness is more akin to a philosophical suite of attitudes than to a spontaneous subjective feeling. If your child leads a good and proper life, filled with moral meaning, he or she might feel deeply satisfied and content. Gilbert uses the Greek word eudaimonia to describe the idea, a word Aristotle translated as “doing and living well.” Eudaimonia literally means “having a good guardian spirit.” •    Judgmental happiness. In this case, the word “happiness” is followed by words like “about” or “for” or “that.” Your child might be happy about going to the park. She might be happy for a friend who just got a dog. This involves making a judgment about the world, not in terms of some transient subjective feeling but as a source of potentially pleasurable feelings, past, present, or future.

Since 1937, researchers for the Harvard Study of Adult Development have exhaustively collected intimate data on several hundred people. The project usually goes by the moniker the Grant Study, named for the department store magnate W. T. Grant, who funded the initial work. The question they are investigating: Is there a formula for “the good life”? What, in other words, makes people happy? Vaillant has been the project’s caretaker for more than four decades, the latest in a long line of scientific shepherds of the Grant Study. His interest is more than just professional. Vaillant himself is a self-described “disconnected” parent. Married multiple times, he has five children, one of whom is autistic and four of whom don’t speak to him very often. His own father committed suicide when he was 10, leaving him with few happy examples to follow. So he’s a good man to lead the search for happiness. The project’s scientific godfathers, all of whom are now dead, recruited 268 Harvard undergraduates to the study. They were all white males, seemingly well-adjusted, several with bright futures ahead of them—including longtime Washington Post editor Ben Bradlee and President John F. Kennedy. Their lives were to be stretched out like a rack for years so that teams of professionals, including psychologists, anthropologists, social workers, even physiologists, could keep track of everything that happened to them. And that’s what they did. With an initial thoroughness the Department of Homeland Security might envy, these men have endured exhaustive medical checkups every five years, patiently taken batteries of psychological tests, tolerated in-person interviews every 15 years, and returned questionnaires every other year, for nearly three-quarters of a century. Though supervised unevenly over the decades by what best might be called a tag team of researchers, the Grant Study is probably the most thorough research of its type ever attempted. And what did they come up with after all these years? What in the end constitutes the good life? Consistently makes us happy? I’ll let Vaillant, in an interview with the Atlantic, speak for the group: “The only thing that really matters in life [is] your relationships to other people.” After nearly 75 years, the only consistent finding comes right out of It’s a Wonderful Life. Successful friendships, the messy bridges that connect friends and family, are what predict people’s happiness as they hurtle through life. Friendships are a better predictor than any other single variable. By the time a person reaches middle age, they are the only predictor.

More research has since confirmed and extended these simple findings. In addition to satisfying relationships, other behaviors that predict happiness include:        •    a steady dose of altruistic acts        •    making lists of things for which you are grateful, which generates feelings of happiness in the short term        •    cultivating a general “attitude of gratitude,” which generates feelings of happiness in the long term        •    sharing novel experiences with a loved one        •    deploying a ready “forgiveness reflex” when loved ones slight you If those things sound obvious—the usual suspects in self-help magazines—this one may be a surprise: Money doesn’t make the cut. People who make more than $5 million a year are not appreciably happier than those who make $100,000 a year, the Journal of Happiness Studies found. Money increases happiness only when it lifts people out of poverty to about $50,000 a year in income. Past that, wealth and happiness part ways. This suggests something practical and relieving: Help your children get into a profession that can at least make around $50,000 a year.

After decades of research burning through millions of dollars, scientists have uncovered this shocker of a fact: We are most likely to maintain deep, long-term relationships with people who are nice. Mom was right. Individuals who are thoughtful, kind, sensitive, outward focused, accommodating, and forgiving have deeper, more lasting friendships—and lower divorce rates—than people who are moody, impulsive, rude, self-centered, inflexible, and vindictive. A negative balance on this spreadsheet can greatly affect a person’s mental health, too, putting him at greater risk not only for fewer friends but for depression and anxiety disorders. Consistent with the Grant Study, those with emotional debits are some of the unhappiest people in the world. Moody, rude, and impulsive sound an awful lot like faulty executive control, and that is part of the problem. But the deficit is even larger. These people are not regulating their emotions.

This kind of filtering is exactly what emotions do in the brain. You’re probably used to thinking of emotions as the same thing as feelings, but to the brain, they’re not. In the textbook definition, emotions are simply the activation of neurological circuits that prioritize our perceptual world into two categories: things we should pay attention to and things we can safely ignore. Feelings are the subjective psychological experiences that emerge from this activation.

By 6 months of age, a baby typically can experience surprise, disgust, happiness, sadness, anger, and fear. What babies don’t have are a lot of filters. Crying for many months remains the shortest, most efficient means of getting a parent to put a Post-it note on them. Parental attention is deep in the survival interests of the otherwise helpless infant, so babies cry when they are frightened, hungry, startled, overstimulated, lonely, or none of the above. That makes for a lot of crying.

These so-called mirror neurons are scattered across the brain like tiny cellular asteroids. We recruit them, in concert with memory systems and emotional processing regions, when we encounter another person’s experiences. Neurons with mirrorlike properties come in many forms, researchers think. In my case, I was experiencing the mirrors most closely associated with extremity pain. I was also activating motor neurons that governed my arm’s desire to withdraw from a painful situation. Many other mammals appear to have mirror neurons, too. In fact, mirror neurons initially were discovered by Italian researchers trying to figure out how monkeys picked up raisins. The researchers noticed that certain brain regions became activated not only when monkeys picked up raisins but also when they simply watched others pick up raisins. The animals’ brains “mirrored” the behavior. In humans, the same neural regions are activated not only when you tear a piece of paper and when you see Aunt Martha tearing a piece of paper—but also if you hear the words “Aunt Martha is tearing a piece of paper.” It’s like having a direct internal link to another person’s psychological experience. Mirror neurons permit you to understand an observed action by experiencing it firsthand, even though you’re not. Sounds a lot like empathy. Mirror neurons may also be profoundly involved in both the ability to interpret nonverbal cues, particularly facial expressions, and the ability to understand someone else’s intentions. This second talent falls under an umbrella of skills called Theory of Mind, which we’ll describe in detail in the Moral chapter. Some researchers think Theory of Mind skills are the engines behind empathy.

Because this type of neural activity easily can be measured, it is possible to ask if every child has an equal talent for empathy. The unsurprising answer is no. Autistic children, for example, have no ability to detect changes in people’s emotional states. They simply can’t decode another person’s psychological interiors by looking at his or her face. They cannot divine people’s motivations or predict their intentions. Some researchers think they lack mirror-neuron activity.

Parents have known for centuries that babies come to this world with an inborn temperament. Scientist Jerome Kagan, who studied Baby 19, was the first to prove it. Human temperament is a complex, multidimensional concept—a child’s characteristic way of responding emotionally and behaviorally to external events. These responses are fairly fixed and innate; you can observe them in your baby soon after he or she is born. Parents often confuse temperament with personality, but from a research perspective they aren’t the same thing. Experimental psychologists often describe personality in much more mutable terms, as behavior shaped primarily by parental and cultural factors. Personality is influenced by temperament the same way a house is influenced by its foundation. Many researchers think temperament provides the emotional and behavioral building blocks upon which personalities are constructed.

So you can see temperament at birth, and it remains stable over time. Does that mean temperament is completely controlled by genes? Hardly. As we saw with the ice-storm children in the Pregnancy chapter, it is possible to create a stressed baby simply by increasing the mother’s stress hormones—not a double helix in sight. The involvement of genes is a scientific question, not a scientific fact. Happily, it is being researched. Studies of twins so far show that there is no one gene responsible for temperament. (Gene work almost always begins with twins, the gold standard being twins separated at birth and raised in different households.) When you look at the temperaments of identical twins, the degree of resemblance, the correlation, is about 0.4. This means there is probably some genetic contribution, but it is not a slam dunk. For fraternal twins and non-twin siblings, the correlation is between 0.15 and 0.18, even less of a slam dunk.

In that game of peekaboo, it is obvious that the baby and his mother have already formed a reciprocating relationship. In the late 1960s, researchers coined a term to describe it: attachment. Attachment theory springs from the finding that babies come into this world preloaded with lots of emotional and relational abilities. At birth, babies appear to express disgust, distress, interest, and contentment. Within six months, they experience anger, fear, sadness, surprise, and joy. Give them another year and they will feel embarrassment, jealousy, guilt, and maybe even pride. These emotions are like RoboCop’s tags (or Post-it notes, if you prefer) telling the brain, “Pay attention to this!” Different kids tag different things. It’s as random as a newborn’s fascination with Dad’s beard, an infant’s distress at wearing socks, or a toddler’s fear or love of dogs. Knowing what your kids tag—what things they have an emotional reaction to—and then responding to that knowledge in specific ways is not only part of the attachment process, but one of the big secrets to raising happy kids.

Parents face many issues on a daily basis in the raising of kids, but not all of them affect how their children turn out. There is one that does. How you deal with the emotional lives of your children—your ability to detect, react to, promote, and provide instruction about emotional regulation—has the greatest predictive power over your baby’s future happiness. Fifty years of research, from Diana Baumrind and Haim Ginott to Lynn Katz and John Gottman, have come to this conclusion. That’s why your child’s emotional life takes the central role, the chicken, in our metaphor. You won’t get any of the other benefits of the recipe unless you have placed the meat of the matter squarely in the center of your parenting behavior. The critical issue is your behavior when your children’s emotions become intense (Gottman would say “hot”) enough to push you out of your comfort zone. Here are the six spices that go into this parental dry rub:        •    a demanding but warm parenting style        •    comfort with your own emotions        •    tracking your child’s emotions        •    verbalizing emotions        •    running toward emotions        •    two tons of empathy

Authoritative: Just right Responsive plus demanding. The best of the lot. These parents are demanding, but they care a great deal about their kids. They explain their rules and encourage their children to state their reactions to them. They encourage high levels of independence, yet see that children comply with family values. These parents tend to have terrific communication skills with their children. Neglecting parents tended to produce the worst-behaved, most emotionally challenged kids on the block; they got the worst grades, too. Authoritative parents produced Doug. Baumrind’s insights were confirmed in a massive 1994 study involving thousands of students as they entered adolescence in California and Wisconsin. Based solely on parenting behavior, researchers successfully predicted how the kids would turn out, regardless of ethnicity.

Emotional surveillance comes with a caveat, however, for it is possible to give too much of a good thing. In the late 1980s, researchers were somewhat startled to find that when parents paid too much attention to their kids’ cues—responding to every gurgle, burp, and cough—the kids became less securely attached. Children (like anybody) didn’t take too well to being smothered. The stifling seemed to interfere with emotional self-regulation, messing with a natural need for space and independence.

“I don’t like it,” the 3-year-old muttered to herself as the guests left. Miserable throughout her older sister’s birthday party, she was now growing angry. “I want Ally’s doll, not this one!” Her parents had bought her a consolation present, but the strategy went down like a lead balloon. The girl threw her doll to the floor. “Ally’s doll! Ally’s doll!” She began to cry. You can imagine a parent making any of several choices in the face of this bubbling brew. “You seem sad. Are you sad?” is what the girl’s dad said. The little girl nodded, still angry, too. The dad continued. “I think I know why. You’re sad because Ally’s gotten all the presents. You only got one!” The little girl nodded again. “You want the same number and you can’t have it, and that’s unfair and that makes you sad.” The dad seemed to be pouring it on. “Whenever somebody gets something I want and I don’t, I get sad, too.” Silence. Then the dad said the line most characteristic of a verbalizing parent. “We have a word for that feeling, honey,” he said. “Do you want to know what that word is?” She whimpered, “OK.” He held her in his arms. “We call it being jealous. You wanted Ally’s presents, and you couldn’t have them. You were jealous.” She cried softly but was beginning to calm down. “Jealous,” she whispered. “Yep,” Dad replied, “and it’s an icky feeling.” “I been jealous all day,” she replied, nestling into her daddy’s big strong arms. This big-hearted father is good at (a) labeling his feelings and (b) teaching his daughter to label hers. He knows what sadness in his own heart feels like and announces it easily. He knows what sadness in his child’s heart looks like, and he is teaching her to announce it, too. He is also good at teaching joy, anger, disgust, concern, fear—the entire spectrum of his little girl’s experience. Research shows that this labeling habit is a dominant behavior for all parents who raise happy children. Kids who are exposed to this parenting behavior on a regular basis become better at self-soothing, are more able to focus on tasks, and have more successful peer relationships. Sometimes knowing what to do is tougher than knowing what to say. But sometimes saying is all that’s needed.

There’s another powerful way to fine-tune a child’s hearing for the emotional aspects of speech: musical training. Researchers in the Chicago area showed that musically experienced kids—those who studied any instrument for at least 10 years, starting before age 7—responded with greased-lightning speed to subtle variations in emotion-laden cues, such as a baby’s cry. The scientists tracked changes in the timing, pitch, and timbre of the baby’s cry, all the while eavesdropping on the musician’s brain stem (the most ancient part of the brain) to see what happened. Kids without rigorous musical training didn’t show as much discrimination. Their brains didn’t pick up on the fine-grained information embedded in the signal and were, so to speak, more emotionally tone deaf. Dana Strait, first author of the study, wrote: “That their brains respond more quickly and accurately than the brains of non-musicians is something we’d expect to translate into the perception of emotion in other settings.” This finding is remarkably clear, beautifully practical, and a bit unexpected. It suggests that if you want happy kids later in life, get them started on a musical journey early in life. Then make sure they stick with it until they are old enough to start filling out their applications to Harvard, probably humming all the way.

How might the attitudes of discouraging or ignoring emotions play out in real life? Imagine that the family goldfish, the only pet your 3-year-old son Kyle has ever known, suddenly dies. Visibly upset, Kyle mopes around the house all day, saying things like “I want fishy back!” and “Bring him back!” You’ve tried to ignore him, but his moodiness eventually grates on you. What do you do? One response might be: “Kyle, I’m sorry your fish is dead, but it’s really no big deal. He’s just a fish. Death is part of life, and you need to learn that. You wipe those tears away, son, and go outside and play.” Another might be: “That’s OK, honey. You know, the fish was already old when you were born. We’ll go to the store tomorrow and get you another one. Now put on that happy face, and go outside and play.” Both responses completely ignore how Kyle is feeling at the moment. One seems to actively disapprove of Kyle’s grief; the other is trying to anesthetize it. Neither deals with his intense emotions. They give him no tools that might help him navigate through his grief. Know what Kyle might be thinking? “If this is not supposed to matter, why do I still have this big feeling? What I am supposed to do with it? There must be something really wrong with me.”

It’s a myth that releasing emotions makes everything better (that blowing your top will defuse your anger, for example). “Better out than in,” the saying goes. Almost half a century’s worth of research shows that “blowing off steam” usually increases aggression. The only time expressing anger in that style helps is when it is accompanied immediately by constructive problem solving. As C. S. Lewis observed in The Silver Chair, one book in the Chronicles of Narnia series: “Crying is all right in its own way while it lasts. But you have to stop sooner or later, and then you still have to decide what to do.”

What exactly does “moral” mean? Are any moral absolutes embedded into our brains, or is moral awareness only culturally understood? These questions have occupied philosophers for centuries. The word “moral,” in both its Greek and Latin incarnations, has a strong social underpinning. It originally outlined a code of conduct, a consensus of manners and customs possessing equal parts “heartily recommend it” and “don’t you dare.” That’s the definition we’ll use: a set of value-laden behaviors embraced by a cultural group whose main function is to guide social behavior. Why would we need such rules in the first place? It may have to do with that strong evolutionary requirement for social cooperation. Some researchers believe our moral sense—really a specific suite of socializing behaviors—developed to aid that cooperation. Regular massacres, after all, are not exactly in the best interests of a species whose effective founding population was less than 18,500 individuals (some say less than 2,000). In this Darwinian view, our brains come preloaded at birth with certain limited moral sensibilities, which then develop in a semi-variable fashion, depending upon how we are raised. “[W]e are born with a universal moral grammar,” says cognitive scientist Steven Pinker, “that forces us to analyze human action in terms of its moral structure …” Popular candidates for which moral sensibilities we possess include distinctions between right and wrong, proscriptions against social violence such as rape and murder, and empathy. Yale psychologist Paul Bloom lists a sense of justice, emotional responses to thoughtfulness and altruism, and a willingness to judge another person’s behavior. Psychologist Jon Haidt sees five categories: harm, fairness, loyalty, respect for authority, and something intriguingly called spiritual purity.

Humans tend to have that altruistic quality in spades, and in much more sophisticated forms than our genetic neighbors. If moral awareness is universal, we might also expect to see general agreement across cultures. Harvard researchers developed the Moral Sense Test, which hundreds of thousands of people from more than 120 countries have taken. You can take it, too, at http://moral.wjh.harvard.edu. The data they’ve compiled appear to confirm a universal moral sense.

Turns out it’s surprisingly difficult to explain proactive moral behavior, like voluntarily helping someone cross the street. Even enlightened self-interest does not fully explain certain types of human altruism. The road between moral reasoning and moral behavior is quite rocky. In fact, the concept of “conscience” was developed in a partial attempt to pave over this difficulty. A conscience is something that makes you feel good when you do good things and makes you feel bad when you don’t. The late Harvard psychologist Lawrence Kohlberg believed that a healthy conscience was the top rung in the ladder of all moral reasoning. But not all scientists think conscience is innate. Some think it’s a social construct. For them, internalization is the most important measure of moral awareness. A child who can resist the temptation to defy some moral norm, even when the possibility of detection and punishment is zero, has internalized the rule. These children not only know what is proper, an awareness that might have been preloaded into their brains, but they now agree with it and attempt to align their behaviors accordingly. This is also sometimes called inhibitory control, which sounds suspiciously like well-developed executive function. They may be the same thing. Either way, a willingness to make the right choices—and to withstand pressure to make the wrong ones, even in the absence of a credible threat or in the presence of a reward—is the goal of moral development. Which means your parenting objective is to get your child to pay attention to and align himself with his innate sense of right and wrong. This takes time. A lot of time.

What is Theory of Mind? A literary example may help explain it. Ernest Hemingway was once challenged to write an entire novel in only six words, and what he wrote is a perfect illustration of Theory of Mind. That’s because when you read it, it will activate yours. For sale: Baby shoes. Never used. Do these six words make you sad? Make you wonder what happened to the person who wrote the advertisement? Can you infer that person’s mental state? Most humans can, and we use Theory of Mind skills to do it. The basis of these skills is the understanding that another’s behavior is motivated by a range of mental states—beliefs, intentions, desires, perceptions, emotions. Theory of Mind, first coined by noted primatologist David Premack, has two general components. The first is the ability to discern someone else’s psychological state. The second is the realization that although these states may be different from your own, they are still valid for the person with whom you are interacting. You develop a theory of how the other person’s mind works, even if it differs from your own.

Kohlberg, the Harvard psychologist, believed that moral reasoning depended upon general cognitive maturity—another way of saying that these things take time. If, indeed, decisions have strong emotional roots, as we will explore, I would also argue that moral reasoning depends upon emotional maturity. Though Kohlberg has his critics, his ideas remain influential, as do those of his intellectual mentor, Jean Piaget. The ideas of both men have been applied in schools, juvenile detention facilities, even prisons. Kohlberg outlined a progressive process for moral development: 1.   Avoiding punishment. Moral reasoning starts out at a fairly primitive level, focused mostly on avoiding punishment. Kohlberg calls this stage pre-conventional moral reasoning. 2.   Considering consequences. As a child’s mind develops, she begins to consider the social consequences of her behaviors and starts to modify them accordingly. Kohlberg terms this conventional moral reasoning. 3.   Acting on principle. Eventually, the child begins to base her behavioral choices on well-thought-out, objective moral principles, not just on avoidance of punishment or peer acceptance. Kohlberg calls this coveted stage post-conventional moral reasoning. One could argue that the goal of any parent is to land here. Kids don’t necessarily arrive at this third stage all by themselves. Along with time and experience, it can take a wise parent to get a child to consistently behave in a manner congruent with his or her inborn moral grammar.

Families who raise moral kids follow very predictable patterns when it comes to rules and discipline. The patterns are not a behavioral insurance policy, but they are as close as research gets us right now. Many interlocking components make up these patterns; an illustration from my wife’s kitchen may simplify things. We used to keep a three-legged stool near the refrigerator to help our boys reach the shelves. Think of the flat seat of that stool as representing the development of a moral awareness, or conscience. Each leg represents what researchers know about how to support it. You need all three legs for the stool to provide children with the sturdiest seat—the most finely attuned moral reflexes. The three legs are:        •    Clear, consistent rules and rewards        •    Swift punishment        •    Rules that are explained

How not to punish kids? Try the 1979 movie Kramer vs. Kramer. The film is about a divorcing couple and the impact of the experience on their young son. Dustin Hoffman plays the workaholic, unengaged dad whose parenting instincts have the subtlety of dog food. The scene opens with the little boy refusing to eat dinner, instead demanding chocolate-chip ice cream. “You’re not going to have any of it until you eat all your dinner,” the dad warns. The son ignores him, gets a chair, and reaches up for the freezer. “Better not do that!” dad admonishes. The kid opens the freezer anyway. “You’d better stop right there, fella. I’m warning you.” The son brings the ice cream to the table, acting as if his dad were invisible. “Hey! Did you hear me? I’m warning you, you take one bite out of that, and you’re in big trouble!” The boy dips the spoon in the ice cream, staring intently at his father. “Don’t you dare! You put that ice cream in your mouth, and you are in very, very, very big trouble.” The kid opens his mouth wide. “Don’t you dare go anywhere beyond that.” When the boy does, his dad snatches him up out of his chair and throws him in his bedroom. “I hate you!” the kid yells. The dad shouts, “And I hate you back, you little shit!” He slams the door. The coolest heads, obviously, were not prevailing. The following four guidelines show the way to punishment that’s actually effective. •    It must be punishment. The punishment should be firm. This does NOT mean child abuse. But it also doesn’t mean a watered-down version of the consequences. The aversive stimulus must, in fact, be aversive to be effective. •    It must be consistent. The punishment must be administered consistently—every time the rule is broken. That is one of the reasons why hot stoves alter behavior so quickly: Every time you put your hand on it, you get burned. The same is true with punishment. The more exceptions you allow, the harder it will be to extinguish the behavior. To borrow a familiar phrase: Let your yes be yes and your no be no. Consistency must be there not only from one day to the next but from one caregiver to the next. Mom and Dad and Nanny and stepparents and grandparents and in-laws all need to be on the same page regarding both the household rules and the consequences for disobeying them. Punishments are obnoxious by definition—everyone wants to escape them—and kids are unbelievably talented at discovering loopholes. You can’t give them the opportunity to play one caregiver against another if you want them to have a moral backbone. All they’ll form is cartilage. •    It must be swift. If you are trying to teach a pigeon to peck on a bar but delay the reinforcement by 10 seconds, you can do it all day and the pigeon won’t get it. Shrink that delay to 1 second, and the bird learns to peck the bar in 15 minutes. We don’t have the same brains as birds, but whether we are being punished or rewarded, we have remarkably similar reactions to delay. Researchers have measured…

Overall, a clear picture emerges about how to raise well-adjusted, moral children. Parents whose rules issue from warm acceptance and whose rationales are consistently explained end up being perceived as reasonable and fair, rather than as capricious and dictatorial. They are most likely to evince from their kids committed compliance rather than committed defiance.

The central fact of newborn sleep is that it is nothing like adult sleep. Instead of gradual cycles of descent and ascent, newborns have only two speeds, christened by sleep researcher Richard Ferber as “active sleep” and “quiet sleep.” Both speeds are established in the womb, detectable by the middle of the third trimester. The presence of just two tempos means infants are only beginning to learn how to sleep. They won’t exhibit a predictable sleep cycle for several months—or adult-like sleep behaviors for years. Sleep for them seems spasmodic, and parents get jerked along for the ride. On a good night, adults ride a smoothly moving elevator. On a good night, babies ride the Tower of Terror. Why? Here’s what researchers know so far: When babies are safely tucked inside their mother’s womb, they may respond to—even follow—mom’s natural biochemical rhythms. This is because they are plugged into the maternal central computer via the placenta and umbilical cord. It’s not just humans. All mammals get warmth, food, water, and hormones (including sleep-regulating melatonin) from mom on a regular basis. At birth, the comforting supply of warmth, food, water, and sleep cues become immediately and violently disconnected. (I literally cut the umbilical cord off both my sons with a pair of sharp scissors.) In this one act, babies become completely out of sync with the cycles of adult existence. The newborn must solve these problems immediately after birth, the most important problem being food. Some researchers think the altered waking/sleeping patterns initially concentrate on getting a consistent food supply. Newborns’ task is Herculean. They need to eat about every two to three hours, some much more often. Consistent with this notion, infant sleep patterns have been shown initially to closely follow feeding patterns: the amount of time it takes babies to consume food, digest food, metabolize food, and then become hungry again. Baby may sleep, but only after the tank has been topped off. Notice that I said “may.” Some babies are energized by food, in which case they are not ready to sleep after a midnight snack; they are ready to play, cry, or otherwise demand attention. So feeding doesn’t always ensure a round of sleep.

want to immediately put their kid in a crib. Frustratingly,

Sleep experts agree that one thing helps babies make this transition: having a consistent bedtime routine. This starts with choosing a time for bedtime, sometime around 6 months old. Around the world, bedtime depends upon baby and culture. Whatever time you choose, the advice is to make it consistent. Next, create a series of predictable bedtime rituals. These rituals can be almost anything, from singing favorite lullabies to turning all the lights in the house down low. Part of the ritual may involve giving your infant a warm bath, followed by a nursing session to “top off” the child before slumber. If the child is a tough sleeper, your routine may involve a slow ride over a bumpy road. The Medina family found this to be the most successful method when sleep was a problem. Whatever the activities, they should be consistently applied: same content, same order, same environment. Babies quickly learn to associate these behaviors, especially when dependably applied, with the fact that sleep time is coming.

Nighttime Attachment Parenting is an extremely infant-driven style. Advocates encourage feeding on demand rather than keeping to a schedule, both day and night; wearing your newborn in a sling during the day; and sleeping with your baby at night (whether in the same bed or in the same room), or at least making “comfort visits” to baby’s crib when baby cries. The idea is to have as much contact with your child as possible. Baby will be calmer and feel secure during the day, NAP advocates argue, and thus baby will be calmer and more likely to sleep at night. Like Athena leaping from the forehead of an elderly Zeus, Nighttime Attachment Parenting styles spring from attachment theories first developed in the late ’60s (discussed in more detail in “Attentive, patient ping-pong,” on page 190). Needs not fulfilled when junior is a baby, the theory goes, create problems for junior as an adult. Ignoring your baby at night is a way of ignoring those needs, say NAP advocates; paying attention is a way of gratifying them. NAP’s champion is the aforementioned William Sears. He is an experienced, handsome pediatrician, the epitome of a California doctor. To say he likes kids is an understatement. He and his wife, a nurse and parenting health advocate, have raised eight children.

It is not often a scientist becomes so engrained in popular culture that his name becomes a verb. But that is exactly what happened to pediatric sleep researcher Dr. Richard Ferber, a prominent advocate of the Cry-It-Out method. Dr. Ferber, founder of Boston’s Center for Pediatric Sleep Disorders, didn’t make up CIO. Core CIO ideas can be found as far back as the 19th century. But his name is so closely associated with the practice that parents who embraced his protocol were accused—yes, accused—of “Ferberizing” their children. How does CIO work? Researchers call CIO methods “extinction styles.” In psychology, “extinction” is a general term for weakening a behavior by restricting its reward structure. The reward structure is attacked because it is the reinforcing agent keeping a behavior alive, a behavior whose extinction is desired. With infant sleep, a reinforcing agent looks like this: (a) baby is crying at 3:00 a.m. for attention; (b) parent comes into the room, picks him up, and comforts him, providing the attention; (c) baby stops crying, thus reinforcing the behavior. The baby learns that crying is a good way to get attention, day or night. He cries in anticipation of parental response, creating an internal attitude called a “reinforcement expectation.” The parent learns that the most successful method to calm the infant at night is to go in and hold him, which rewards the crying. The way to “break” this cycle is to not provide attention every time baby wants it. He must instead be taught to fall back asleep independently, CIO advocates say. Baby then learns to sleep on his own, and the nighttime crying is extinguished. This process is not usually greeted with enthusiasm on the part of the child. That’s why it’s called “crying it out.” CIO can properly be described as a continuum between “unmodified extinction,” in which the parent refuses to respond regardless of how long the crying continues (researchers don’t recommend this), and “camping out” or “fading,” in which the parent is close but spends less and less time by the child’s crib providing assurance. In the middle of the continuum, we find “graduated extinction.” The parent does respond to the child’s nighttime cries, but on a strict schedule. The amount of time a child is allowed to cry gradually lengthens. The delays are deliberately timed and incremental, hence the term “graduated.”

Remember, baby is not your enemy in his struggle to learn to sleep independently, just a very inexperienced ally. Your goals are naturally aligned, after all. From an evolutionary perspective, it is in his brain’s best interest to learn how to stay awake during the day, then learn to sleep through the night. Though it is as much a struggle for him to get it right as it is for you to teach him, you can’t give up. After all, that’s the heart and soul of parenting. The constant theme of this book is that babies are people, but they are not adults. You have to teach them everything. At least at first, you have to be willing to be the professor 24 hours a day.

The real world of moms and dads is a much richer, much more amazing experience than the two-dimensional world of data, including all the stuff in this book. It’s easy to feel like the exasperated new father in the comic strip Baby Blues, who says, “The only time I ever felt qualified to be a parent was before I had kids.” How can we summarize the science but still live in the nine-to-five, three-dimensional world of real life? The solution is to simplify.

You may think that grown-ups create children. The reality is that children create grown-ups. They become their own person, and so do you. Children give so much more than they take.

Seeing his personality blossom was truly a gift. This is the message I want to leave you with as we part ways. As a new parent, you may feel sometimes that all children do is take from you, but it is just a form of giving in disguise. Kids present you with an ear infection, but what they are really giving you is patience. They present you with a tantrum, but they are really giving you the honor of witnessing a developing personality. Before you know it, you’ve raised up another human being. You realize what a great privilege it is to be a steward of another life. I said that parenting is all about developing human brains, but my aim was inches too high. Parenting is all about developing human hearts. There is no idea in this book more important for new parents than that one.

Schedule sex regularly Yes, the great joy in physical intimacy includes a healthy helping of spontaneity. Problem is, you can kiss spontaneity out the window when you bring baby home. Sexual activity usually plummets after the birth of a child, and the loss of associated emotional intimacy can be devastating for couples. Scheduling sex—however often is right for you—can buffer against this tendency. It also gives each partner time to mentally decompress and get into the mood. Try incorporating two types of sex into your lives: spontaneous sex and maintenance sex.

There may be as many different types of playrooms as there are families, but every one of them should have the following design element: lots of choices. A place for drawing. A place for painting. Musical instruments. A wardrobe hanging with costumes. Blocks. Picture books. Tubes and gears. Anything where a child can be safely let loose, joyously free to explore whatever catches her fancy. Did you see the movie Willy Wonka & the Chocolate Factory? If so, you may have been filled with wonder at the chocolate plant, complete with trees, lawns, and waterfalls—a totally explorable, nonlinear ecology. That’s what I mean. I am focusing on artistic pursuits because kids who are trained in the arts tend to resist distractions better, stay focused better, and have better scores on fluid intelligence tests. My wife and I devoted nearly 600 square feet in our house to creating such an environment, filled with music stations, reading and drawing and painting and crafting areas, lots of Legos, and lots of cardboard boxes. There was a math and science station, including a toy microscope. We changed the contents of these stations on a regular basis, and we eventually turned the space into our kids’ classroom.