Ashley Merryman and Po Bronson spent a lot of their days saying things such as “good job”, “great work!” and “how clever!” to children, almost until they were hoarse. Ashley had founded a centre that coached deprived children in Los Angeles, and felt that even if praise might not make up for their damaged lives, she was damn well going to try. Po, well, he was a middle-class author and father-of-two living in San Francisco, and praise is what middle-class parents now do to their children. Their praise, they thought, came from a mix of instinct and researched good practice. They were wrong on both counts.

“When I found out what praise actually did, I was quite horrified,” says Ashley.

“I’d been working with underprivileged kids, telling them, ‘you’re wonderful’. And when I read the effects of that, I was stunned. I was angry. I felt, why didn’t anyone tell me about this before?”

And Po, when he got the news, he put his family into “praise cold turkey”.

“I realised I was going to change the way I spoke to my children overnight.”

Surveys of parents show that nearly all now believe it’s important to tell their children they are bright and talented, to boost their confidence and therefore achievement. It’s a theory of self-fulfilling prophecy, born of the self-esteem movement of the 1970s.

But then Ashley and Po stumbled across the work of Carol Dweck, a Stanford professor. She has proved, in a growing body of work dating back 15 years, that telling a child they are bright causes the opposite result. It didn’t prevent underperforming – it could actually cause it.

In one study on 400 nine-year-olds in New York, telling them the six words “you must be smart at this” before a test reduced their scores by 20 per cent. This after just a single sentence, let alone the barrage of praise that pummels a typical Western child at school and beyond.

The pair didn’t set out to demolish the prevailing wisdom on education, but that is what happened. Did you know, for example, that asking your teen to be more grateful may be a cause of their unhappiness? That emotionally literate “educational” television may give your child the sophistication to become a better bully? That racially mixed classrooms haven’t led to less racism? And that there is really only one thing that will predict whether your children will get along together? Childcare – like health – is extremely vulnerable to bad science and false prophets because the adults involved are anxious enough to jump on any advice that is in vogue.

The response to Ashley and Po’s subsequent magazine article on praise was overwhelming, and so was born NurtureShock, a book that Po describes, in publicist-speak, as “Freakonomics for kids”. It’s no surprise that this book was an instant bestseller in America, tapping into two of the modern world’s most highly marketable formats. The first, the endless supply of parenting books that offer conflicting advice according to the fads and fashions of the time. The second, the new trend for authors such as Malcolm Gladwell or the Freakonomics team to popularise social science, which some argue also cycles according the fads and fashions of the time.

So, I was doubtful, especially about the book’s subtitle “Why everything we think about raising our kids is wrong” (really, everything? Even the bit about how they’ll be just fine if you just stop reading the parenting books?) Ashley and Po are journalists (and long time friends) rather than academics. They compensate with the breadth of their research. Ashley claims that for the ten topics the book covers, from the link between obesity and lack of sleep to the dangers of educational television, they read a total of 200,000 pages of research journals.

Credibility is key for them. The pair were so appalled by the wrongheaded advice they had previously taken on trust, that they are now the scourge of bad science in homes and classrooms. Parents have a natural instinct to love and protect their children, yes, but most of the rest of their actions are “polluted by a hodge-podge of wishful thinking, moralistic biases, contagious fads, personal history and old disproven psychology”, they write, as a kind of mission statement.

You only have to look, Ashley told me, at the different upbringing of your grandparents to see how subject the process is to historical forces. What if, now social science has sharpened up its act, it could end the cycles, and establish a definitive “right” way to educate, even if it is so counter to what we currently believe to be true? That is the NurtureShock vision.

If not achievable, it is certainly thought-provoking. The chapter on praise demolishes the current vogue for cherishing our children’s every dab of paint. Instead, in order for praise to work, it has to be limited, sincere, and about effort rather than achievement. A meta-analysis of 150 praise-studies by Stanford University in 2002 found that praised students become risk-averse, try less and are less selfmotivated. Even pre-schoolers are vulnerable to the inverse power of praise – and bright girls especially so. Dweck’s research showed that the girls with the highest IQ, when told they were bright before the test, collapsed to the point that they performed lower than the lowest IQ girls. A review of 200 studies on high self-esteem by the American Association for Psychological Science found that it did not improve exam results or career achievement, or reduce violence or alcoholism.

Interestingly, when Po stopped praising so much, he found it was he, rather than his son, who felt the withdrawal. “I recognised that praising him with the universal ‘you’re great, I’m proud of you’ was a way I expressed unconditional love. Offering praise has become a sort of panacea for the anxieties of modern parenting.”

This became the theme of the book: how adults have projected policies on to children, because it is the adults themselves who benefit from or are attached to them. Take racial integration in schools – a project that America has devoted itself to with gusto since the civil rights movement of the 1960s. Liberal adults believe that exposing children to other skin colours early on is enough. But, NurtureShock states, “this is more of a fantasy than fact”. In some places, making schools more diverse increased racist attitudes. Studies also show that white parents, in particular, are uncomfortable talking to their children about race: the younger their children, the more uncomfortable the parent. But, in fact, there may be a crucial window – as young as five – when explicit discussion of racism has the most positive effects.

Or what about the growing number of parents who are anxious about only children having poor social skills? Instead, the authors found that children may “learn poor social skills from sibling interactions, just as often as they learn good ones”. This is reflected in children’s books and television programmes. Even in those that were promoted to help siblings get along, much time was spent showing siblings taunting, belittling and blaming. And, the studies found, children aren’t reassured by the happy ending nearly as much as adults. This is why, when shown supposedly positive books about siblings, their own fraternal relations became even more fractious.

So what can a parent do? Most fret about the age gap or gender mix of their children – but the studies showed this had no impact on how well brothers and sisters got along. Instead, it rested largely on how well the older child played with his or her friends before the next baby was born. Then, the pattern was set by the older child’s lead from a very early age.

Alternatively, choosing the right school for your child could also have significant effects on their social skills and overall behavior. Whether you are looking for the best private schools in houston or any other places for that matter, you might want to make sure your child gets the adequate exposure and is in an environment that supports their growth.

Educationalists have long tried to make children happier, by trying to cure children’s problems an adult way. Anti-drugs programmes in school? Mostly all a very costly failure – a study of America’s most popular one, which claims influence over 26 million students at an annual cost of over $1 billion showed no long term effects (part of the reason teenagers do drugs is to defy authority such as this). A radical new programme to teach teenagers how not to be bored? A failure (teenagers are genetically programmed to be bored). Here’s an interesting one: gratitude journals. When adults are asked to list the positives in their life they are thankful for, on a daily or weekly basis, it has been shown to lift their mood. When tried on young teenagers, it flopped. In fact, it made some teenagers even more downcast.

This is because teenagers have a strong urge towards independence. “Their lack of gratitude,” NurtureShock explains, “might be the way they maintain the illusion they are in control of their lives. They didn’t feel happy that people were always there doing things for them. It made them feel powerless.”

All this should be stirring news, but I actually finished the book rather depressed. It chronicles a litany of attempts inspired by science – to improve children’s lives, all adopted with enthusiasm. They have at best wasted time, effort and money, and at worst damaged young people in the name of progress. It only seems to be accelerating: as recently as 1990s the fad for “Emotional Intelligence” was in full force, until a study showed that convicted prisoners had higher “EQ” than the rest of the population. For me it cast politicians, parents and teachers as their own mad scientists, driven by their ambition to experiment on their young.

I put this to the authors: did it knock your faith in science as it did mine? Oh no, they both said. The opposite. “This book is correcting a lot of crap that’s been fed to society for over 100 years,” says Po. “What was fun for us was not to feed the flame of all the fads, but to snuff it out to some extent. People say, scientists have been wrong in the past, therefore today’s science must also be wrong. But what was wrong was that most of these programmes took a nugget of science and ran with it. You’ve got to look hard at the data. If this book makes people sceptical of educational initiatives, then great.”

Why don’t we just forget about it, I say, bin the books, do what feels right? No, they insist. It’s almost as if they believe science has a chance of ridding childhood of its emotional and educational horrors, just as it has of its medical ones.

Po believes science could save us. “The way we parent matters. Look at disaffected youth, their anger at authority leads to crime, and ultimately, to terrorism. Is NurtureShock going to change that? No. But slight changes can make a big difference, long term, and alter the character of our society.”

Or, as Ashley, always a little more modest than Po, says: “I’ve been working with kids a long time. Science gave me a key to understanding them – I was surprised by how much more interesting they are now. To me, it makes kids exciting.”

Tips for getting it right

The authors of NurtureShock are against tips. “We didn’t set out to write a parenting manual,” says Ashley. “We didn’t want to give tips in the book. We respect parents and educationalists, we trust them to figure it out.” Still, if you read the book, you might form these conclusions:

1 Limit the praise of children, and focus on effort rather than achievement. Do not praise “innate” gifts.

2 Talk to children about racism at an early age.

3 A child’s dishonesty is a sign of intelligence and social savvy.

4 The child who is a bully is often extremely popular too – they use their superior emotional skills for good and ill.

5 Siblings do not compete over parental love, but over possessions.

6 Books and videos for children about repairing sibling relationships more often lead to further deterioration.

7 Instead work on encouraging the older child’s friendships and seeing the younger as a proxy friend through fun activities.

8 Teenagers rate arguing with their parents more positively than parents – they see it as a welcome opportunity to stop lying to adults.

9 Make sure your child gets enough sleep: the loss of one hour for an 11-year-old is the equivalent of slipping to the academic level of a nine year old.

10 In teenagers the loss of each hour of sleep sent the odds of obesity up by 80 per cent.