Little Arran Fernandez is not sure whether he wants to be a lorry driver, space explorer or a mathematician.

He was reading and doing sums at two and a half and now, at five, has a GCSE in maths.

At eight, Dylan Cobb, has just passed GSCEs in maths and information technology at grade B.

The boys are following in the footsteps of many other child prodigies.

The most famous is Ruth Lawrence, who went to Oxford University at the age of 12 - the youngest person to do so.

Arran Fernandez wants to be a mathematician or a lorry driver

Now working at the University of Jerusalem and a mother of two, she says she will not "hot-house" her children.

Many education experts believe children like Arran and Dylan might have been better off if they had been kept out of the examination system until they were teenagers.

Professor Joan Freeman has just published a book on the lives of people who were singled out as gifted children.

In "Gifted Children Grown Up", she traces their lives from the age of five to 35.

She found those who were pushed to exam success too young often ended up as disappointed adults.

"I can't understand why people enter their young children for exams, unless it's parental pride," she said.

"What is this five-year-old going to do for an encore?

"Just sticking the label "gifted" on a child is asking for trouble."

Gifted children

Parents who believe their children to be very bright will not be encouraged to put them in for exams early if they look for advice from the National Association for Gifted Children.

The organisation's education consultant, Jo Counsell, said she could not understand why parents opted for early exams.

"I don't know if it's harmful if the support is good, but I also don't know what they are trying to achieve.

"In a way, it's a cruel kind of experiment.

She said children should be encouraged in their interests and taken to interesting places to feed their minds and imaginations.

"I'm against hot-housing, because that is forcing a child in the way a plant can be forced."

Ronald Ryde: "Children are motivated by doing exams"

But parents like Neil Fernandez - Arran's father - believe they are doing the best for their children.

A political economist who educates his son at home, he says Arran is a happy child.

"Arran is a normal child and has a lot of friends," he said.

One man who firmly believes in pushing bright children is Ronald Ryde, who founded Ryde College near Watford where Arran and Dylan took their exams.

He said taking the exams early was worthwhile: "It motivates them and gives them an interest and also helps them develop confidence.

"If they get a GCSE at a young age then when it comes to doing exams at school later on they won't be worried about it.

It's a cruel kind of experiment

Jo Counsell, National Association for Gifted Children

"At school there is very little education until about the age of 14 and then very quickly they are expected to take exams in about nine different subjects.

"I think that is a lot more pressured. If a child takes one or two exams at different ages there is no pressure."

But Professor Freeman - of Middlesex University - says the problem for young high-achievers is that eventually other children catch up.

"I believe many children could take their GCSEs early if they were tutored and hot-housed.

"But there are much more important things in life than passing GCSEs early.

"Children's social and emotional needs must be met too," she said.