In 2007, Dr. Greg Duncan published a ma.s.sive a.n.a.lysis of 34,000 children, with no less than eleven other prominent co-authors. They combed through the data from six long-term population studies-four of which were from the United States, one from Canada, and one from the United Kingdom. Prior to kindergarten, the children partic.i.p.ating all took some variety of intelligence test or achievement test. As well, mothers and teachers rated their social skills, attention skills, and behaviors-sometimes during preschool, sometimes in kindergarten. The scholars sought out data on every aspect of temperament and behavior we recognize can affect performance in school-acting out, anxiety, aggression, lack of interpersonal skills, hyperactivity, lack of focus, et cetera.

Duncan's team had expected social skills to be a strong predictor of academic success, but, Duncan recalled, "It took us three years to do this a.n.a.lysis, as the pattern slowly emerged." On the whole the IQ tests showed the degree of correlations as in Suen's meta-a.n.a.lysis: combining math and reading together, early IQ had at best a 40% correlation with later achievement. The attention ratings, at best, showed a 20% correlation with later achievement, while the behavior ratings topped out at an 8% correlation. What this means is that many kids who turned out to be very good students were still fidgety and misbehaving at age five, while many of the kids who were well-behaved at age five didn't turn into such good students. That social skills were such poor predictors was completely unexpected: "That is what surprised me the most," confirmed Duncan.

It's tempting to imagine one could start with the 40% correlation of IQ tests, add the 20% correlation of attention skill ratings, and top it off with a social skills measure to jack the total up to a 70% correlation. But that's not how it works. The various measures end up identifying the same well-behaved, precocious children, missing the children who blossom a year or two later. For instance, motivation correlates with academic success almost as well as intelligence does. But it turns out that kids with higher IQs are more motivated, academically, so every a.n.a.lysis that controls for IQ shows that motivation can add only a few percentage points to the overall accuracy.

Almost every scholar has their own pet concoction of tests, like bartenders at a mixology compet.i.tion. At best, these hybrids seem to be maxing out at around a 50% correlation when applied to young children.

In a later chapter of this book, we'll discuss measures that get at the skill of concentrating amid distraction-how this may be the elusive additive factor scientists are looking for. And it could be that in a few years, a scholar will emerge with a hybrid test of IQ and impulsivity that will predict a five-year-old's future performance. Until then, it needs to be recognized that no current test or teacher ratings system, whether used alone or in combination on such young kids, meets a reasonable standard of confidence to justify a long-term decision. Huge numbers of great kids simply can't be "discovered" so young.

With IQ test authors warning that kids' intelligence scores aren't really reliable until a child is around 11 or 12, that raises a fascinating question. What's going on in the brain that makes one person more intelligent than another? And are those mechanisms substantially in place at a young age-or do they come later?

Back in the 1990s, scientists were seeing a correlation between intelligence and the thickness of the cerebral cortex-the craterlike structure enveloping the interior of the brain. In every cubic millimeter of an adult brain, there's an estimated 35 to 70 million neurons, and as many as 500 billion synapses. If the nerve fibers in a single cubic millimeter were stretched end to end, they would run for 20 miles. So even a slightly thicker cortex meant trillions more synapses and many additional miles of nerve fibers. Thicker was better.

In addition, the average child's cortex peaked in thickness before the age of seven; the raw material of intelligence appeared to be already in place. (The entire brain at that age is over 95% of its final size.) On that basis, it could seem reasonable to make key decisions about a child's future at that stage of development.

But this basic formula, thicker is better, was exploded by Drs. Jay Giedd and Philip Shaw of the National Inst.i.tutes of Health in 2006. The average smart kid does have a bit thicker cortex at that age than the ordinary child; however, the very smartest kids, who proved to have superior intelligence, actually had much thinner cortices early on. From the age of 5 to 11 they added another half-millimeter of gray matter, and their cortices did not peak in thickness until the age of 11 or 12, about four years later than normal kids.

"If you get whisked off to a gifted cla.s.s at an early age, that might not be the right thing," Giedd commented. "It's missing the late developers."

Within the brain, neurons compete. Unused neurons are eliminated; the winners survive, and if used often, eventually get insulated with a layer of white fatty tissue, which exponentially increases the speed of transmission. In this way, gray matter gets upgraded to white matter. This doesn't happen throughout the brain all at once; rather, some parts of the brain can still be adding gray matter while other regions are already converting it to white matter. However, when it occurs, this upgrade can be rapid-in some areas, 50% of nerve tissue gets converted in a single year.

The result can be leaps in intellectual progress, much like a dramatic growth spurt in height. During middle childhood, faster upgrading of left hemisphere regions leads to larger gains in verbal knowledge. The area of the prefrontal cortex considered necessary for high-level reasoning doesn't even begin upgrading until preadolescence-it's one of the last to mature.

In those same years, the brain is also increasing the organization of the large nerve capsules that connect one lobe to another. Within those cerebral superhighways, nerves that run parallel are selected over ones that connect at an angle. Slight alterations here have whopping effects-a 10% improvement in organization is the difference between an IQ below 80 and an IQ above 130. Such 10% gains in organization aren't rare; on the contrary, that's normal development from age 5 to 18.

With all this construction going on, it's not surprising that IQ scores show some variability in the early years. From age 3 to age 10, two-thirds of children's IQ scores will improve, or drop, more than 15 points. This is especially true among bright kids-their intelligence is more variable than among slower children.

Dr. Richard Haier is an eminent neurologist at University of California, Irvine. When I told him that New York City was selecting gifted students on the basis of a one-hour exam at age five, he was shocked.

"I thought school districts ended that practice decades ago," Haier said. "When five-year-olds are tested, it's not clear to me that having a single snapshot in the developmental sequence is going to be that good, because not every individual progresses through development at the same rate. What about the kid who doesn't progress until after age five?"

Haier's specialty is identifying the location of intelligence in the brain. Neuroscience has always been obsessed with isolating the functions of different brain regions. Early findings came from patients with damage to discrete regions; from what they could not do, we learned where visual processing occurs, and where motor skills are stored, and where language is comprehended.

In the last decade, brain-scanning technology enabled us to decipher far more-we know what lights up when danger is imminent, and where religious sense is experienced, and where in the brain lie the powerful cravings of romantic love.

But the search for intelligence in the brain lagged. At last, neuroscientists like Haier are on the verge of identifying the precise cl.u.s.ters of gray matter that are used for intelligence in most adults. But during their hunt, they collectively discovered something that has made them rethink the long-held a.s.sumption that ties brain location to brain function.

As a child ages, the location of intellectual processing shifts. The neural network a young child relies on is not the same network he will rely on as an adolescent or adult. There is significant overlap, but the differences are striking. A child's ultimate intellectual success will be greatly affected by the degree to which his brain learns to shift processing to these more efficient networks.

Dr. Bradley Schlaggar, a neurologist at Washington University in St. Louis, has found that both adults and children called upon 40 distinct cl.u.s.ters of their gray matter when subjects performed a simple verbal test inside an fMRI scanner. However, comparing the scans of the children (age 9) to adults (age 25), Schlaggar saw that only half of those cl.u.s.ters were the same. The adults were utilizing their brains quite differently.

Similarly, Dr. Kun Ho Lee of Seoul National University gave IQ puzzles to two groups of Korean high schoolers inside a scanner. The brains of the smart teens had shifted processing to a network recruiting the parietal lobe; they tested in the top one percent. The brains of the normal teens had not made this shift.

Other scholars are finding this as well. Teams at Cornell, Stanford, and King's College, London, have all found that children's cognitive networks aren't the same as adults'.

"This is so contradictory to the old principles of neuroscience," remarked a gleeful Haier. "The research is going in a new direction, that intelligence moves throughout the brain as different brain areas come online."

From the unfinished cortex to the shift in neural networks, none of the critical mechanisms of intelligence are yet operational at the age most children are taking a test for entry into a gifted program or a private K through 8 school. We are making long-term structural decisions over kids' lives at a point when their brains haven't even begun the radical transformations that will determine their true intelligence.

Real intellectual development doesn't fit into nicely rounded bell curves. It's filled with sharp spikes in growth and rough setbacks that have to be overcome.

We need to question why this idea of picking the smart children early even appeals to us. We set this system up to make sure natural talent is discovered and nurtured. Instead, the system is failing a majority of the kids, and a lot of natural talent is being screened out.

It may sound trite to ask, "What about the late bloomers?" But in terms of truly superior cognitive development, the neuroscience suggests that "later" may be the optimal rate of development. And it's not as if society needs to wait forever for these later developers to bloom; the system of screening children would be significantly more effective if we simply waited until the end of second grade to test them.

It's common for gifted children to make uneven progress. (It's not unheard of for a gifted child's scores across verbal and nonverbal skills to be so disparate that one half of a test result could qualify for an advanced program while the other half could send the kid to special ed.) The way most programs are currently designed, admissions officers never consider that uneven development may actually be an a.s.set. The young child who masters cognitive skills but struggles in phonics might later approach the abstract language of poetry in a profoundly new way. A four-year-old's single-minded fascination with dinosaurs to the exclusion of anything else might not mark a deficit; instead, it might allow him to develop focus and an approach to learning that will serve him well in any other context.

Think of the little girl kept out of a gifted program-despite the fact that she'd been reading since she was two-because she wasn't manually coordinated enough to put four blocks in a perfect row.

In the meantime, the late-blooming child lives with the mistaken fact that she is not gifted-but she's bright enough to understand that the Powers That Be have decreed that it would be a waste of time and resources to develop her potential. The gifted rolls have already been filled.

SIX.

The Sibling EffectFreud was wrong. Shakespeare was right. Why siblings really fight.

In Brazil recently, a team of scholars studied the medical data from an emergency room, looking at all the cases where children had been rushed in after swallowing coins. The scholars were curious-was swallowing coins more common for children who didn't have any brothers or sisters? In the end, they decided their sample size was too small to draw any conclusion.

This was far from the first time scholars had tried to find strange side effects of being an only child. In Italy, a couple years ago, researchers tried to determine if female onlies were more likely to have an eating disorder in high school. (They weren't.) In Israel, one scholar noted that onlies had higher incidence of asthma-at least compared to children who had 15 to 20 siblings. But compared to children with a normal number of siblings, there was barely any difference in the rate of asthma. Parents of onlies could stop worrying.

Meanwhile, over in the United Kingdom, researchers were studying whether onlies get fewer warts. Not that you need to know the answer, but what the heck-onlies do have somewhat fewer warts at age 11. However, Scottish researchers have informed us that onlies get more eczema.

It seems that research on onlies has gone batty. It's no surprise why. In the last two decades, the proportion of women having only one child has about doubled in the United States, and single-child families are now more common than two-child families.

n.o.body knows what this means for the children, but it seems reasonable that it must mean something. something. We have this idea because we've always stigmatized the exception, and onlies are a good example of that: way back in 1898, one of the pioneers of child psychology, G. Stanley Hall, wrote that "being an only child is a disease in itself." Many scholars today cringe at this ridiculous statement, but the studies on warts and coin swallowing suggest some are still under the influence of Hall's point of view. We have this idea because we've always stigmatized the exception, and onlies are a good example of that: way back in 1898, one of the pioneers of child psychology, G. Stanley Hall, wrote that "being an only child is a disease in itself." Many scholars today cringe at this ridiculous statement, but the studies on warts and coin swallowing suggest some are still under the influence of Hall's point of view.

Scientists have uncovered some things about onlies-where onlies measure out slightly differently than those with brothers and sisters. But these are not surprising discoveries. We know that onlies do a little bit better in school, on average-probably for the same reasons that oldest siblings do a tiny bit better than younger siblings. From a study in Australia we know that girl onlies average fifteen fewer minutes of physical activity per day, which probably explains the study in Germany that said preschool-aged onlies have slightly worse physical dexterity.

But that's not what society worries about, when it comes to onlies. What we wonder is: "Do they know how to get along?" Nowhere is this question getting more scrutiny than in China, which has limited families in urban areas to one child since 1979. (Despite this policy, 42.7% of families in China today have two or more children.) When the policy was first implemented, critics argued that a country of onlies would destroy the character of the entire nation. Despite three decades of intense study on this question, the research in China is still very mixed. One report said onlies in middle school were less less anxious and had anxious and had better better social skills. But another report stated that in high school it was just the opposite. The research on social skills is just as conclusive in China as the coin-swallowing research in Brazil. social skills. But another report stated that in high school it was just the opposite. The research on social skills is just as conclusive in China as the coin-swallowing research in Brazil.

Why are we seeing no clear effect? It's surprising, because the theory theory that being an only child deprives a child of social skills makes so much logical sense. By growing up with siblings, a child has thousands upon thousands of interactions to learn how to get along. According to this theory, children with siblings should be ma.s.sively more skilled at getting along than children with no siblings. that being an only child deprives a child of social skills makes so much logical sense. By growing up with siblings, a child has thousands upon thousands of interactions to learn how to get along. According to this theory, children with siblings should be ma.s.sively more skilled at getting along than children with no siblings.

Yet they aren't.

Maybe the mistake here was a.s.suming that those thousands upon thousands of interactions with siblings amount to a single positive. Perhaps the opposite is true-that children learn poor social skills from those interactions, just as often as they learn good ones.

Dr. Laurie Kramer, a.s.sociate Dean at the University of Illinois at Urbana-Champaign, is attempting to do the impossible: get brothers and sisters to be nicer to each other.

It was clear what she's up against, after just a few minutes with parents who have enrolled their children in Kramer's six-week program, "More Fun with Sisters and Brothers." We were sitting on a circle of couches in a small room, watching their children on a closed-circuit television. On the other side of the wall, in a living room wired with seven hidden cameras, the children were working with Kramer's undergraduate students.

"When they get going, it's a like a freight train. It's paralyzing," remarked one mother about the fighting between her five-year-old daughter and six-year-old son. In her professional life, she's a clinical psychiatrist working with wounded veterans. But it's seeing her kids battling that she described as "painful to watch."

Another mother sighed in frustration as we watched her seven-year-old son constantly taunt his four-year-old sister. "He knows what to say, but he just can't be nice about it." She stared into s.p.a.ce for a moment, fighting a tear.

A mother of five-year-old twin girls felt that her kids are usually great together-but for some inexplicable reason, they can't get through cooking dinner without a nightly argument.

The families in Kramer's program are well-educated and well-off. Many of the parents are Illinois faculty, and their children attend one of the best private elementary schools in Urbana. These parents have done everything to provide their children with a positive environment. But there's one wild card in the environment that they can't control, undermining everything-how well the siblings get along.

Mary Lynn Fletcher is the program coordinator for Dr. Kramer; she's on the receiving end of the phone calls from parents who want to get their kids in the program. "Many are shaking when they call. My heart goes out to them," Fletcher said. "They are so stressed. Others, the stress isn't so bad, but they are feeling so helpless. Every day, there's a moment they have to deal with. One parent was driving her kids home from school, and she said, 'Listen to this,' then held the cell phone up to the back seat so I could hear the yelling."

It might sound like these children were the problem cases, but Ashley and I had reviewed videotapes of the children made a month earlier, in their homes. Each tape recorded a half-hour stretch of the sibling pairs playing beside each other with their toys, without any parents in the room to mediate. On these videotapes, there was definitely some tension, but what we saw looked better than normal.

Observational studies have determined that siblings between the ages of three and seven clash 3.5 times per hour, on average. Some of those are brief clashes, others longer, but it adds up to ten minutes of every hour spent arguing. According to Dr. Hildy Ross, at the University of Waterloo, only about one out of every eight conflicts ends in compromise or reconciliation-the other seven times, the siblings merely withdraw, usually after the older child has bullied or intimidated the younger.

Dr. Ganie DeHart, at State University of New York College at Geneseo, compared how four-year-old children treat their younger siblings versus their best friends. In her sample, the kids made seven times as many negative and controlling statements to their siblings as they did to friends.

Scottish researcher Dr. Samantha Punch found similar results in her interviews of ninety children. She determined that kids don't have an incentive to act nicely to their siblings, compared to friends, because the siblings will be there tomorrow, no matter what. She concluded, "Sibship is a relationship in which the boundaries of social interaction can be pushed to the limit. Rage and irritation need not be suppressed, whilst politeness and toleration can be neglected."

So do they grow out of it, by having thousands of interactions of practice? Not really, according to Kramer. Back in 1990, she and her mentor, Dr. John Gottman, recruited thirty families who were on the verge of having a second child; their first child was three or four years old. Twice a week, for months, Kramer went into their homes to observe these siblings at play until the youngest were six months old. She was back again at fourteen months, then four years. Each time, Kramer scored the sibling relationship quality, by coding how often the kids were nice or mean to each other. Nine years later, Kramer tracked these families down again. By then, the older siblings were on the verge of college. Again, she videotaped them together. To make sure they didn't ignore each other, she gave the sibling pairs some tasks-solve some puzzles together, and plan an imaginary $10,000 weekend for their family.

Kramer learned that sibling relationship quality is remarkably stable over the long term. Unless there had been some major life event in the family-an illness, a death, a divorce-the character of the relationship didn't change until the eldest moved out of the house. For the most part, the tone established when they were very young, be it controlling and bossy or sweet and considerate, tended to stay that way.

"About half of these families are still in the Urbana-Champaign area," said Kramer. "They're now into their twenties. I see their graduation and wedding announcements in the paper. I b.u.mp into their parents at the grocery store. I ask how they're getting along. It's really more of the same."

Kramer often hears, "But I fought with my brothers and sisters all the time, and we turned out great." She doesn't disagree. Instead, she points out that in many sibling relationships, the rate of conflict can be high, but the fun times in the backyard and in the bas.e.m.e.nt more than balance it out. This net-positive is what predicts a good relationship later in life. In contrast, siblings who simply ignored each other had less fighting, but their relationship stayed cold and distant long term.

Before she began "More Fun with Sisters and Brothers," Kramer had parents fill out questionnaires about their expectations for their children's sibling interactions. The parents actually accepted conflict as a way of life for siblings; instead, what really troubled them was that their children so often just didn't seem to care care about each other. Their feeling toward their brother or sister was somewhere between blase ambivalence and annoyance. about each other. Their feeling toward their brother or sister was somewhere between blase ambivalence and annoyance.

So Kramer's program is unique in the field-she doesn't attempt to teach children some kinder version of conflict mediation. Grownups have a hard enough time mastering those techniques-attentive listening, de-escalation, avoiding negative generalizations, offering compliments. Instead, the thrust of Kramer's program is made in its t.i.tle-getting siblings to enjoy enjoy playing together. The six hour-long sessions are meant to be a fun camp for siblings to attend. Most activities that kids have scheduled into their lives are age-segregated-siblings go off with children their own size. Here, they stick together. playing together. The six hour-long sessions are meant to be a fun camp for siblings to attend. Most activities that kids have scheduled into their lives are age-segregated-siblings go off with children their own size. Here, they stick together.

In the first session, four papier-mache hand puppets appear on a puppet stage. They announce they're alien children from the planet Xandia. The clouds on Xandia produce rain whenever brothers and sisters argue, and the planet is at risk of flooding. The aliens have come to Earth to attend the camp with the human children, in order to learn how to have more fun together. All the children-alien and earthling-spend the next six sessions playing board games, creating art projects, role playing, and dancing to a custom-made rap song. They take home bedtime books and a board game set on Xandia.

Along the way, the children adopt a terminology for how to initiate play with their siblings, how to find activities they both like to do together, and how to gently decline when they're not interested. They consciously role play these steps. What these steps are called (Stop, Think, and Talk) probably isn't important; what's crucial is the kids are given a way to bridge the age-divide, so the older child doesn't always end up in a bossy role. During one of the sessions, the children are visited by an annoying woman in trench coat named Miss Busy Bossy-she's a clownlike caricature of a boss, too busy to even put down her cell phone. The children teach her to be less bossy.

Many of the games and art projects teach the kids to recognize the feelings being broadcast in the faces of their siblings. The catchphrase they're taught is, "See it your way, see it my way." They draw these facial expressions on paper plate masks, then listen to stories and hold up the masks that correspond to how each child in the story would be feeling.

Kramer has fine-tuned her scripts for the sessions over the years, but probably the most innovative aspect of her program isn't in those details-it's that she focuses on the children at all. Other scholars a.s.sumed that four-year-olds were too young, so they directed their training at parents, trying to coach them how to respond to sibling fights. In Kramer's program, fewer fights are the consequence consequence of teaching the children the proactive skills of initiating play on terms they can both enjoy. It's conflict of teaching the children the proactive skills of initiating play on terms they can both enjoy. It's conflict prevention prevention, not conflict resolution resolution. Parents are mere facilitators; when back at home, their job is to reinforce the rule that the kids should use their steps together to work it out, without without the parents' help. the parents' help.

Kramer's program is effective, by every measure. The before-and-after videotapes of the kids playing at home reveal more positive, mutual involvement, and the parent questionnaires indicate the parents spend less time breaking up arguments between the kids. The children seem to enjoy the camp, but an hour never goes by without at least one cla.s.sic display of sibling tension, as the older child turns controlling, or the younger plays the provocateur. In fact, the entire premise of the camp-the idea that brothers and sisters should enjoy enjoy one another-is an objective not all kids are ready to accept. one another-is an objective not all kids are ready to accept.

"I have two special talents," seven-year-old Ethan announced to the instructors and the children in the program. "The first is soccer with my dad. The second is I'm really good at beating people up. When I beat my sister up, it makes me feel good."

His four-year-old sister, Sofia, sat not more than two feet away from him as he said this. But she didn't react to his shocking claim.

The truth was that Ethan had never actually hit his sister, who was half his size. Instead, he often fretted that she was so tiny that he might accidentally hurt her. But that session, Ethan seemed to delight in being verbally cruel to Sofia. He mocked her-loudly protesting when an instructor helped her read aloud. He said he didn't want a younger sister: "She wants to play princess, and she always wants me to be the prince, but I want to play ninja. Right now, she's really annoying, and not a worthy opponent."

At the end of the session, Ethan's mother confronted him in the hallway, demanding an explanation. Ethan made a particularly insightful point: "But Mom, it's not cool cool to like a little sister." to like a little sister."

Ethan was convinced he had to act act mean toward Sofia. He couldn't let the other older siblings in the program know that he liked his sister-thus the false brag about beating her up. mean toward Sofia. He couldn't let the other older siblings in the program know that he liked his sister-thus the false brag about beating her up.

Curious about how Ethan and Sofia really got along, we sat down with Kramer to watch the videotape of them at home. Over the half-hour, Ethan led Sofia in the construction of a fort made of couch cushions. The tension was excruciating; it felt like a scene out of film noir-a ba.n.a.l little event that could explode into tragedy at any moment.

Designating himself construction manager, Ethan bossed the four-year-old around constantly. He yelled and chided her when she couldn't hold a cushion perfectly straight. When she wanted to leave for a snack, Ethan threatened, "If you do one more thing-you'll lose your job and you can't come back." When Sofia misunderstood something, the seven-year-old snapped, "No excuses! There are no excuses! You can only keep your job if you promise never, ever to make up an excuse ever again. And don't talk with your mouth full!"

However, Kramer actually saw a lot of hope in the tape. Without question, Ethan berated his sister-but the two kids had chosen, on their own, to play together, and they remained engaged in joint play the entire time. They didn't hit each other. They kept talking. Ethan threatened his sister, but he changed the rules so she could keep playing. He made an effort to help Sofia understand she had an important role in the game. When he stopped ordering her around, Sofia would ask him for guidance-which he delighted in. When Sofia tried to drag a big cushion to the fort, Ethan said, "Good job," then came over to help her.

"The kids are still connected," Kramer ultimately concluded. "There's an attempt to manage conflict. The kids like each other-they are looking out for each other. I think there's a lot to work with." She had not yet scored this tape, but at a glance she estimated it would rate a 50 out of 100-an equal balance of negative and positive moments. "I would imagine, in their tape after the program, they'll be around a 70."

So if Ethan actually liked his sister, where was he getting the message that it was uncool and he had to hide it? Ethan's mother, Rebecca, pointed out that Ethan's best friends all were nice to their little brothers and sisters. It wasn't coming from them. She believed Ethan was picking up the message from the books he was reading. He was an exceedingly gifted reader and consumed books constantly.

Rebecca was reticent to mention her theory, afraid it might come off that she was looking for a scapegoat. However, Kramer's research suggests that Rebecca may be right on target. In one of her studies, Kramer had a control group of kids come in for six weeks of reading books aloud and discussing cartoons that depicted sibling story lines. These were typical products any parent might share with his kids, hoping they would help the kids get along better-the Berenstain Bears series, Sesame Street Sesame Street books, and the like. Kramer figured these kids' relationships with their siblings would improve, but she crossed her fingers that they wouldn't improve books, and the like. Kramer figured these kids' relationships with their siblings would improve, but she crossed her fingers that they wouldn't improve more more than the kids in than the kids in her her program. program.

But Kramer started getting complaints from parents after just a couple weeks. While the books and videos always ended on a happy note, with siblings learning to value and appreciate each other, the first half of the stories portrayed in vivid detail ways that children can fight, insult, and devalue their siblings. "From these books, the kids were learning novel ways to be mean to their younger siblings they'd never considered," Kramer recalled. Sure enough, after six weeks, the sibling relationship quality had plummeted.

Kramer went on to a.n.a.lyze 261 common children's books that portray sibling relationships. These ranged from picture books for preschoolers to chapter books for third graders. Kramer scored the books as she might score a videotape of kids playing together. She noted the number of times a sibling argued, threatened, excluded, and teased, as well as the positive moments of sharing, affection, problem-solving, and inclusion. The average book demonstrated virtually as many negative behaviors as positive ones. Despite all but one being overtly crafted to have a happy ending, along the way kids were constantly taunting each other, belittling a sib, and blaming others for their wrongdoing.

It turns out that Shakespeare was right, and Freud was wrong. For almost a century, Freud's argument-that from birth, siblings were locked in an eternal struggle for their parents' affection-held huge influence over scholars and parents alike. But Freud's theory turns out to be incomplete. Sibling rivalry may be less an Oedipal tale of parental love, and more King Lear.

A team of leading British and American scholars asked 108 sibling pairs in Colorado exactly what they fought about. Parental affection was ranked dead last. Just 9% of the kids said it was to blame for the arguments or compet.i.tion.

The most common reason the kids were fighting was the same one that was the ruin of Regan and Goneril: sharing the castle's toys. Almost 80% of the older children, and 75% of the younger kids, all said sharing physical possessions-or claiming them as their own-caused the most fights.

Nothing else came close. Although 39% of the younger kids did complain that their fights were about... fights. They claimed, basically, that they started fights to stop their older siblings from hitting them.

Mindful of the Freudian paradigm, the scholars tempered their findings, wondering if the children were too young to understand the depths of the family psychodrama they were starring in. But these brothers and sisters weren't toddlers. The younger kids were in elementary school, and some of the older kids were already teenagers. The scholars felt that the psychological community needed to recognize that "siblings have their own repertoire of conflict issues separate from their parents." The struggle to win a greater share of parental love may be a factor, they wrote, but kids in mid-childhood don't think about it, recognize it, or articulate it.

Laurie Kramer also came to this same conclusion. She reviewed 47 popular parenting manuals, a.n.a.lyzing how much of their advice regarding sibling relationships was rooted in empirical research, versus how much was just unproven theory. Kramer found that every single parenting manual recited the psychodynamic paradigm, that sibling resentment stems from a loss of parental attention when the younger child is born. Kramer noted that there's certainly research making this point. For instance, one recent study showed that an older sibling's jealousy when the younger is 16 months old predicts what kind of relationship they'll have a couple years later. But Kramer feels this fixation on compet.i.tion for parental love masks and distracts from a more important truth: even in families where children are given plenty of affection by both parents, "young children may fail to develop prosocial relationships with their siblings if n.o.body teaches them how." Less emphasis needs to be placed on the psychology, and more needs to be on skill-building.

What else is overrated? Parents imagine that the difference in age between siblings is an important factor. Some think it's preferable to have kids less than two years apart, so they are close enough in age to play together; others feel they should wait three or four years, to help each child develop independence. But the research is entirely mixed-for every study that concludes age differences matter, there's another study proving it doesn't. "Relative to other factors," said Kramer, "age s.p.a.cing is not as strong a predictor. Nor is gender. There's many other things to be concerned about."

As for what does matter, Kramer's work offers one big surprise. One of the best predictors of how well two siblings get along is determined before before the birth of the younger child. At first glance, this is astounding-how can it be possible to predict a clash of personalities, if one of the personalities at issue doesn't even exist yet? How can their future relationship be knowable? But the explanation is quite reasonable. It has nothing to do with the parents. Instead, the predictive factor is the quality of the older child's relationship the birth of the younger child. At first glance, this is astounding-how can it be possible to predict a clash of personalities, if one of the personalities at issue doesn't even exist yet? How can their future relationship be knowable? But the explanation is quite reasonable. It has nothing to do with the parents. Instead, the predictive factor is the quality of the older child's relationship with his best friend with his best friend.

Kramer studied young kids from families who were expecting another child. She observed these kids playing one-on-one with their best friends. The kids who could play in a reciprocal, mutual style with their best friend were the ones who had good rapport with their younger sibling, years later.

It's long been a.s.sumed that siblings learn on one another, and then apply the social skills they acquire to their relationships with peers outside the family. Kramer says it's the other way around: older siblings train on their friends, and then apply what they know to their little brothers and sisters.

After monitoring these relationships with best friends, Kramer saw that one factor stood out as especially telling: shared fantasy play. As Kramer and John Gottman explained, "Fantasy play represents one of the highest levels of social involvement for young children." In order for joint fantasy play to work, children must emotionally commit to one another, and pay attention to what the other is doing. They have to articulate what's in their mind's eye-and negotiate some scenario that allows both their visions to come alive. When one kid just announced the beginning of a ninja battle, but the other wants to be a cowboy, they have to figure out how to still ride off into the sunset together.

If, however, the child hasn't developed these good habits on friends, and the younger sibling comes along, now there's very little incentive to learn the skills of shared play (choosing an activity both can enjoy, inviting the other and/or asking to be included, recognizing when someone is busy or wants to play alone). The incentive's not there because, as Samantha Punch pointed out, the sibling will be there tomorrow no matter what. Siblings are prisoners, genetically sentenced to live together, with no time off for good behavior. There is simply no motivation to change.

Kramer also considered children's behavior in day care and preschools. The fact that kids could cooperate in cla.s.s or remain engaged in a group setting didn't predict improved sibling relationships. It was that real connection between friends-that made a child care how his behavior impacted someone he liked-that was the catalyst for the difference.

"A parent is going to work hard to meet his child's needs. They are highly motivated by love," Kramer explained. "Other kids don't care if you're hungry or have a bruise on your knee-they have one, too."

In other words, getting what you need from a parent is easy. It's getting what you want from friends that forces a child to develop skills.

"It's not that parents are unimportant," Kramer has concluded. "But they are important in very different ways."

Which is why, in a sense, what Kramer is really trying to do is transform children's relationships from sibship to something more akin to a real friendship. If kids enjoy one another's presence, then quarreling comes at a new cost. The penalty for fighting is no longer just a time-out, but the loss of a worthy opponent.