Children should have time to play poker, drive go-karts and climb trees, a leading headmaster has warned.
The twin pressures of exams and health and safety mean that today's youngsters are left with little time to develop life skills and enjoy their childhood, according to Christian Heinrich, chairman of the Boarding Schools' Association (BSA).
Mr Heinrich accused private senior schools of being more interested in a child's intelligence than their other abilities, and attacked the tests used by many of these schools to decide which pupils to admit. He also warned that children must be allowed time to play and take risks without punitive health and safety rules.
In his speech to the BSA's annual conference in Brighton, Mr Heinrich will say: "Those long hours in our schools offer a wider co-curriculum alongside the extended core of academic subjects, certainly, but also a greater chance to develop the qualities that we would all wish our children to have in spades: the very qualities that hold together society. The qualities that suggest there is more to society than just the individual and family.
"Children and young adults learn about sharing and borrowing, about others' feelings, concerns and priorities, about self-control and perseverance and, perhaps most importantly, about curiosity, in an environment in which it is possible and much encouraged to learn safely from your mistakes rather than to repeat them.
"So I exhort children at my school: 'Climb trees! Cook your own lunch! Drive a go-kart around the car-park (cordoned off!). Even play poker!'. There's more to school than classrooms and exams. Make mistakes whilst the consequences can be managed and the lessons learned."
Speaking ahead of the conference, Mr Heinrich, who is also head of Cumnor House School, a prep school for four to 13-year-olds in Sussex, told the Press Association that the nature of a boarding school means that there is more time for additional activities outside of the curriculum.
"The other angle is that we as a sector, just like the state sector, have become more pressurised to achieve particular scores in different cognitive ability tests, at nine, 10, 11 and 12. To an increasing degree our senior schools are using these rather bland and sometimes quite harsh tests to decide whether to take children. They do not take into account their full abilities."
These tests are only interested in how intelligent a child is, he said. "That's the least important thing about a child at that stage. The most important thing is have they had the opportunity to develop, and to do that we have got to let them do as much as possible, not just sit in rows or at round tables in classrooms."
Dr Christopher Ray, chairman of the Headmasters' and Headmistresses' Conference (HMC), which represents the headteachers of around 250 leading private schools in the UK and Ireland, said: "There is a shared understanding that every child is different and that assessment must enable each school to identify their strengths and weaknesses. All HMC members give high regard to the report from a pupil's existing head. All HMC members remain committed to developing the whole child."