England's "Victorian" exams system is "unimaginative" and failing to prepare children for the modern working world, Eton's headmaster has warned.
Tony Little argued that it is "misleading" to focus only on areas such as exam results, as there is a risk that this then becomes more important than education overall.
And he suggested that England should be wary of attempting to copy highly academic schooling in areas of the Far East such as Shanghai in China, as they are now looking at the value of giving children an all-round education.
In a Viewpoint article for the Radio Times, Mr Little, who is due to retire from his post at the world-famous private boys' school attended by David Cameron, the Duke of Cambridge and Prince Harry next year, gave his backing to teachers from a Lancashire primary school who recently found themselves in the spotlight after a letter they sent to pupils telling them not to worry about their test results went around the globe.
Pupils in their final year at Barrowford Primary School in Nelson, Lancashire, all received a copy of the letter, signed by headteacher Rachel Tomlinson and Year 6 teacher Amy Birkett, after receiving their SATs results.
It told the youngsters that the school was proud of them and their efforts during the tests, but went on to say that the tests do not assess all of what makes each of them "special and unique" before going on to list a number of talents, abilities and qualities that they possess which are not measurable in exams.
In his article, Mr Little said he was interested by the public response to the letter, which saw the message either as "an overdue and necessary personal support of children, or a betrayal of their futures".
He wrote: "I have some sympathy with the criticism. We have a national tendency to underestimate what young people are capable of achieving academically, in some cases dramatically so, and our expectations should be high. We should allow no excuse for poor teaching. A sharp focus on performance is a good thing, but there is a great deal more to an effective and good education than jostling for position in a league table. The Lancashire teachers were right - there are many ways of being smart.
"For a start, measuring only the easily measurable, such as exam results, can be misleading. There is a real risk that the measurable parts become more important than the whole. And we compound the problem by having an unimaginative exam system, little changed from Victorian times, which obliges students to sit alone at their desks in preparation for a world in which, for much of the time, they will need to work collaboratively."
Mr Little went on to say that he had recently spoken to a top school leader in Shanghai who was concerned that their school system was being stifled by tough university entrance exams, and was looking to Britain for inspiration on how to teach youngsters the skills they need to work in a global economy.
"Here is the irony; we seem intent on creating the same straitjacket the Chinese are trying to wriggle out of," he wrote.
"We should be wary of emulating Shanghai just as they themselves see some value in the liberal values of an all-round education - something we have traditionally been good at."
A Department for Education spokeswoman said: "We make no apology for holding schools to account for the results their pupils achieve in national tests and public examinations. Parents deserve to know that their children are receiving the very best possible teaching. But all good schools know that there is no tension between academic success and an excellent all-round education."