Boys and girls should be educated in separate classes because their brains are hard-wired to learn in different ways, a controversial book says.

Too many schools are creating an environment that is “toxic” to boys, turning them off learning and leaving them quite unprepared for adult life, according to Leonard Sax, a family doctor and research psychologist from Washington DC.

For the past decade parents and teachers have become worried increasingly about boys, who are now routinely outperformed by girls at every level and who show growing levels of disaffection and lack of motivation.

In his book Boys Adrift, Dr Sax argues that this yawning gender gap is the result of innately differently learning styles of boys and girls, and that most classrooms play to the strengths of girls.

“In the co-educational classroom so many of the choices we make are to the advantage of girls, but disadvantage boys,” he said. “The fact that girls are doing well is not the problem. The problem is, why can’t their brothers do as well?”

Dr Sax, founder of the National Association for Single Sex Public Education in the United States, believes the answer lies in subtle, but important differences in the brains of boys and girls.

“Until ten years ago, people said that boys are spatial and girls are verbal. That’s nonsense. There is not much difference in how girls and boys think, but there are differences in how they see and hear,” he told The Times at the start of a lecture tour of boys’ schools in Britain.

Boys, for example, do not hear as well as girls. So a female teacher with a soft voice may believe that a boy who is not paying attention is playing up, when actually he cannot hear her properly. Her reaction may be to discipline him. But Dr Sax says that she would get better results by speaking louder and moving purposefully around the classroom.

Boys’ eyes also respond better to movement and direction, while girls’ eyes are more affected by colour and texture. Asked to draw, five-year-old girls produce flowers, pets and people. Boys will draw a car crash, but may be reproached by teachers for producing something that is “not nice”.

Similarly, he says, although most girls can sit still from a young age, most boys need to be active to discover their own pace. “Asking a five-year-old to sit still and read and write is something that many girls can do, but many boys can’t. I have visited more than 200 schools. This is what I hear the teachers saying, ‘Jason, why are you standing?’, ‘Gerard, are you making a buzzing noise?’, ‘Robert, can you stop tapping?’, ‘Look at Emily, she’s sitting still and is good’.

“The message that boys are getting from the age of 5 is that doing what the teacher wants is unmasculine,” Dr Sax says.

One result, Dr Sax believes, is the overdiagnosis of attention deficit disorder among boys who are considered inattentive by teachers. Parents and doctors are tempted to treat this with medication, when simply putting them in a boyfriendly classroom would be far more effective.

The failure of schools to understand why gender matters means that boys very often switch off from learning from an early age and never reengage. Long after their sisters have gone to university, they are still trapped at home suffering from “failure to launch” into adult life.

The solution, Dr Sax believes, lies in single-sex education provided by teachers trained to understand the differences in brain function between boys and girls.

“Let boys tap the table. Let them jump up from their seat when asked to spell a word. It won’t disturb the boy next to them. Girls are bothered by extraneous noise levels 10 to 40 times lower than the levels that bother men. Girls are aware of what is going on around them. Boys are oblivious,” Dr Sax says.

When such these methods were used in single-sex classes in Florida, pass rates for primary school fourth-grade boys (Year Three in Britain) rose from 55 per cent to 85 per cent.

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