With each step I am more certain," Julie Andrews sings to herself as she marches into her first job as a nanny in the The Sound of Music. "Everything will turn out fine. I have confidence the world can all be mine, They'll have to agree I have con-fi-dence in ME."

All my working life I have tried to emulate this attitude. If only I could muster some “con-fi-dence in ME”, the world would be mine, too. I never bothered to ask if this approach was right because obviously it is. Everyone admires people who are confident. Everyone wants to instil confidence in their children. If I look at one of mine – who was born believing that he was a thoroughly good thing – it is perfectly clear to me that he has won the genetic jackpot.

Even people who do not take the Sound of Music as seriously as they ought to agree that confidence matters. When Michelle Obama (who has inexplicably said she prefers It's a Wonderful Life to The Sound of Music) visited an inner-city school in London a few years ago, she
told the students: "Your success will
be determined by your own confidence and fortitude."

Cicero, who sadly died some 2,000 years before the musical was written, agrees: "With confidence you have won before you have even started."
Even Samuel Johnson believed that "self-confidence is the first requisite
to great undertakings".

But it seems all of us have got it wrong. There is nothing good about being confident. According to a persuasive recent book, Confidence, by Tomas Chamorro-Premuzic, a professor of business psychology at University College London, it's better to be unconfident.

For a start, the unconfident try harder as they are driven on by anxiety. They
also listen to criticism and try to adjust accordingly. And they are far less likely
to become arrogant, hubristic monsters. This makes a great deal of sense. The book is not advocating inferiority complexes all round, but is pointing out what ought to be obvious: we should be realistic about what we are capable of doing or not doing. That way, we are more likely both to get better and to win friends and influence people along the way.

Success
There is no shortage of studies connecting confidence to success. However, Chamorro-Premuzic has come up with data suggesting the causality goes the other way. Barack Obama, Sir Richard Branson and Madonna might all be confident. But their confidence didn't cause their success: it was the success that caused their confidence. He argues we should stop our obsession with self-belief – which risks turning us all into lazy narcissists – and focus on competence. We should
not aim to believe we are good at what we do, we should instead aim simply to be good at it.

What is so strange about this fantastically sensible conclusion is how heretical it is. I don’t think I have ever read a management book that said competence is what matters. I have read plenty that bang on about excellence – which in itself is an overconfident and deluded aim when you think how incompetent most people are.

In the UK, incompetence reigns more than ever: a recent OECD study has shown how British 20-year-olds are dunces
at maths compared with their parents
and grandparents. What Mrs Obama ought to have told those schoolchildren was to concentrate on learning their multiplication tables.

Simple and useful
It is all so elementary. But still companies seem unable to think clearly about competence – which is simple and useful – and have turned it into something complicated and useless involving "key competencies". Professional services firm KPMG, a big employer of graduates, does not tell prospective hires it expects them to be good at long division or spelling. It says it is looking for people with seven "key competencies", including such waffly traits as "delivers quality" and "drives inclusion".

In our quest to get better at what we do, we are permitted one small role for confidence by Chamorro-Premuzic. Sometimes it makes sense to pretend to be confident to signal to others that they should trust us. But we should fake it only up to a point. If you pretend to be much better than you are, you tend to get rumbled.

Which I find, much to my relief, means The Sound of Music was right all along – even if the First Lady and Cicero were not. The point about Maria is that she isn't confident at all. "Oh help," she says, when she sees the size of the entrance to the Von Trapp home. So she sings the song to psych herself into a frame of mind in which she dares to open the gate and present herself to the seven hostile children inside. – (Copyright The Financial Times Limited 2013)