It’s 8.30am, and in the hall of a Merseyside special school loud salsa music plays while staff pump the thermos flask for coffee and arrange themselves on three rows of chairs. Edwin Hammill appears in front of them, dark and dapper in white jeans, rubbing his palms together and promising two days of Inset fun.

The sedately named Mr Hammill looks like the magician David Copperfield, has a pot pourri of an accent encompassing Spanish, Glaswegian and Cockney, and makes extensive theatrical use of his eyebrows. Despite the humorous approach - “Any smokers? Hands up, be proud”; “If I see heads nodding after lunch, don’t worry, I won’t leave you to struggle on your own” - Mr Hammill’s topic is the serious subject of managing difficult behaviour in schools.

The 41-year-old, Mexican-born psychologist is on a mission to train teachers to “explore the verbal option to the limit” with challenging pupils - and so avoid the need for physical restraint. The purpose of his two and three-day courses, delivered through his company Nehmitz, is to “develop teachers’ skills and confidence and make schools safer and less stressful”.

Penkford technology school - the only special school in the country with technology status - has all the immediate hallmarks of a good school: pleasant staff toilets, the offer of coffee (in a Penkford millennium mug) before you’re over the doormat, and a small, cherished case of hard-won trophies and certificates on the wall over the photocopier. But Penkford, like scores of other special schools around the land, is changing.

Formerly a school for children with moderate learning difficulties, now almost half its 130 pupils have emotional and behavioural problems, usually combined with learning difficulties. This, by anyone’s standards, is a challenging population. All staff have been trained in assertive discipline and physical restraint, although the latter is used only as a last resort.

“We’re trying to bite the bullet through extra training,” says acting headteacher Dave Hartley, who has been in the school for 18 years. “There are difficulties, obviously, and people have to want to deal with that kind of child.” The decision to bring in Edwin Hammill came after deputy head Dave King, responsible for pastoral care, went on the Nehmitz course earlier in the year. “I could see what Edwin Hammill was talking about, and the whole programme seemed to fit into the style I would want for our school,” says Mr King.

Edwin Hammill has a BSc in psychology and a masters in applied psychology. He has a funky overhead projector, a laser pen to point up items on the screen and a selection of get-happy music. He’s followed his own management chestnut of the six Ps - “pre planning prevents piss-poor performance” - and made a preliminary visit to meet staff and children. What he doesn’t have, though, is any teaching experience, which might explain his almost humble approach to the 30 Penkford teachers, technicians and learning support assistants gathered here today. “What am I bringing to you that you don’t already know?” he asks, voicing the thoughts of many of his audience. “I don’t bring you mighty solutions. But for the next two days, I’m going to ask for your patience. Because you never know.”

His basic thesis is that improved communication can defuse anger. He spells out to teachers how to be neither aggressive nor passive with the children in their care, but assertive. His flip chart, for the moment, remains empty. “There’s no formula, no arrows to follow.” Human responses are addressed as the complex and unpredictable phenomena they are, but he presents the basic principles of communication, pointing out with wit and charm that the adult attributes of moralising, judging and providing solutions are barriers to effective communication. Even praise can alienate. “You go up to David, who’s doing really well, and tell him his work is good. ‘No it’s not. It’s shite’, he says, and throws it across the room.”

Despite the assumed diffidence, Edwin Hammill is passionate about the methods he promotes. He delivers his talk with his whole body, sometimes almost growling, pacing the floor, gesticulating and occasionally making little rabbit hops to add emphasis. “Behaviour, we learned.” Hop. “None of us were born with be - hav - iour.” Communication is what he is all about. Under stress, he says, people misunderstand each other, teachers and children just as much as lovers, friends or family members. In school, these conditioned, confrontational responses can lead to violence - much of which may be avoidable.

“Most conflict has some kind of beginning and some kind of end and along the way we say things to each other,” he says, prowling an imaginary stage at the front of the hall. “Wouldn’t it be nice in this situation of conflict to know what to do?” Wouldn’t it just. The reality in mainstream and special schools is that when children “blow”, they can end up being physically restrained by two or three staff members. Even when physical injury is avoided, the resulting emotional damage affects the pupil, the teachers and the whole institution.

Increased empathy with pupils, postulates Edwin Hammill, can bring down the emotional temperature. “My principal objective,” he gets the staff to write in their handbooks, “is to ask myself how I would feel if I was in their shoes.”

The Penkford pupils, aged 10-16, are represented in the hall by a creditable display of artwork and their creative rubbings-out on the whiteboard. “Today’s men” it reads. “Hoppe ham, spring veg sou, sponge and custa.” Literacy difficulties are common among pupils, who, at 16, may have a reading age of eight or nine.

They’re represented too by a documentary Edwin Hammill shows early on in the two-day course. A BBC Panorama team installed a camera in the living room of a young couple with a small boy who, even at the start of his primary school career, was highly aggressive and difficult to manage. It’s a distressing reminder of what some children experience at home, as looming step-father Bobby crouches down on film to shout into five-year-old Peter’s face that if he doesn’t “stop fucking around and get ready for school you’ll be locked in your room all day”.

“Don’t fucking shout at me,” the mother screams at the child, when he turns to her. “Get in the fucking kitchen.” The parents want to change, but they can’t. “I haven’t got the inner serenity. There’s something fucking wrong with me,” says stepfather Billy to the psychiatrist, recalling his own terrifying childhood.

“Just like some of our parents,” staff say at coffee time, standing in the sunshine by the newly mown banks of grass outside the classrooms. “Pupils come here in Year 8 or 9 and their needs are so deep and so complex that we just can’t meet them,” says one committed but frustrated teacher. Some staff feel overwhelmed by the aggression, volatility and unpredictability of some pupils’ behaviour, which they have to manage alongside highly vulnerable and withdrawn children.

So what can Edwin Hammill tell them that they don’t already know? Interestingly, his starting point is not the shortcomings of the pupils but those of the staff. “Let’s address our own personal weaknesses,” he says. “Have you got a short fuse? Or helpfulness. Are you always being helpful, when helpfulness is not required? Finding solutions, finishing off other people’s sentences?” Ripples of laughter rise from the room. Working in a school like Penkford forces teachers more than anything else to confront themselves. “Some of these children have learning difficulties,” says Edwin Hammill. “But they’re incisive. They get to know what turns you on, what turns you off, what makes you tick. And they press your buttons.”

He tries constantly to temper his message with realism, acknowledging that staff with a class full of children have only limited time to give “attentive silence” to a child acting out his or her fear and anger. But he gives them techniques for calming angry parents and children, without acting as a lightning rod for the anger, and points out the physiological aspects of rage - increased heart rate, adrenaline and other fight-or-flight hormones released into the bloodstream - which can make reasoning impossible. Instead he advocates “reflective listening”, of the rather stilted kind familiar from some parenting manuals. “You’re angry, Brian, because you feel Mr Pierce has been picking on you.” He likens the principles to a foreign language, which needs to be practised to roll off the tongue. “Is there any such thing as unstructured communication?” he asks, pre-empting the criticism that the technique is too rule-oriented.

By the end of the first day, he appears to be winning staff round. “It’s working on me,” says one. “It focuses your ideas. It’s a refinement of what you’re already doing but it’s helpful,” says another. On day two, most have complied with his instruction to wear something bright “because the sunshine comes from within”. Our man Edwin is in multi-coloured Kickers and a lime-green batik shirt, leopard-like walk unimpaired by a night in a hotel bed. He has his bottled water at the ready, and moisturiser for his hands and elbows, and, like any experienced teacher, asserts his authority in the calling of the register, mildly humiliating people by commenting on their outfits.

But teachers clearly enthuse him. Even late in day two he delivers with passion the notion that children can be empowered for life by skilled teachers. “These children are pushing for breakdowns in relationships, because it is familiar to them. The huge challenge to teachers is not to respond as other adults in their lives have done, by blaming them and reinforcing their rock bottom self-image.” The atmosphere is suddenly grave, and hanging in the room almost tangibly is the huge volume of child distress and despair that rests on these people’s shoulders. “Special schools need special people,” he says. “For many of the pupils, you are the only source of effective inter-personal skills available.”

Edwin Hammill’s own multinational background - he has a Mexican mother and a German birth father but was educated in Singapore and adopted by his British stepfather - offered its own challenges. “In spite of my energy levels and tendency to question everything, I was a well-intended child,” he says. “Through the assistance and belief of adults, I got through.” All children want to be loved, or liked, he reminds them.

The Nehmitz approach was developed for health service workers at risk from members of the public. The sideways move into working with teachers began after an approach from the National Association of Head Teachers in the early Nineties. Edwin Hammill believes the course is equally relevant to mainstream schools - “if staff in mainstream schools were better trained, a percentage of the children would not end up in special schools” - but most participants come from special schools.

Some of the 60-or-so schools that have brought in Hammill to train staff have given enthusiastic endorsement. “We highly recommend the Nehmitz approach to behaviour management,” write staff of Ripplevale school in Kent. The consistent child-centred approach is fostering stability among their pupils, they go on to say. “Staff have responded with continued and increased confidence in difficult situations,” says the headteacher of Larwood school in Hertfordshire.

Penkford head Dave Hartley is pleased too. “The response has been good,” he says. “We certainly intend to take up his ideas.”

Nehmitz can be contacted at 16 Bourne Close, Chantry Green, Calcot, Reading, Berkshire RG31 7BD. Tel: 0118 941 0940