People who went to public school are "so dominant across society" not because of their academic achievements but because of the "grounding in soft skills" they get at independent schools, a former head of several leading public schools believes.
Dr Anthony Seldon, who was head of Wellington College in Berkshire from 2006 until earlier this year, will give a speech where he will say that the "remorseless drive in state schools for exam success is no longer fit for purpose".
He will tell Tatler magazine's first School's Live! conference that pupils need to learn skills such as teamwork, empathy and resilience to equip them for life beyond the classroom.
Dr Seldon, who is now Vice-Chancellor of the University of Buckingham, will say: "Independent schools are taking the lead nationally in preparing students for the jobs required for the 21st century.
"The reason why alumni from independent schools are so dominant across society is not just because of the excellent exam results they receive, but precisely because of the grounding in the soft skills.
"The remorseless drive in state schools for exam success is no longer fit for purpose. Students certainly need to be skilful at maths, science, languages and humanities. But they also need those skills that computers cannot replicate."
He will quote a recent Harvard University study, which found that employers need far more than the skills developed in exams - they also need "what is patronisingly called the 'soft' skills... of creativity, teamwork, empathy, grit, resilience and honesty".
Dr Seldon, who was head of Brighton College from 1997 to 2005, will say he believes Education Secretary Nicky Morgan is the "first secretary of state fully to appreciate that schools can excel at academic rigour and at teaching character, wellbeing and the soft skills that the 21st century economy and society require".
"Though the best state sectors manage to teach both for exams and for skills, the state sector overall has much to learn from the success of the British independent school model," he will add.
The Schools Live! event in central London features lectures and discussion panels made up of education experts, with topics expected to be covered including single sex versus co-educational schooling and exam pressure.
A Department for Education spokeswoman said: "It is vital that every child, regardless of their background, gets an education which allows them to realise their potential. That's why we have placed high expectations at the heart of our schools, with a rigorous new curriculum, world class exams and an accountability system that rewards those schools which help every child to achieve their best.
"Alongside this we are investing £5 million in character education to help pupils develop the grit and resilience they need to succeed in school and later life, while giving teachers the freedom to develop lessons that will excite and inspire their pupils."