Most quarrels in the school playground are among the girls, say the Primary 7 mediators at St Mark's Primary in Barrhead, East Renfrewshire. But that doesn't mean only girls can help resolve them.
Personal qualities are vital to a mediator: being a girl is not.
"The first thing you have to do when people come to you with a problem is listen to their story," says young Anthony McCool. "Then you make suggestions for what they can do next."
That first listening step is essential and can't be rushed, explains Erin Sullivan. "I knew you'd have to be patient to be a mediator. I didn't realise just how much patience you would need."
Peer mediation was introduced at St Mark's in June 2002, when a dozen youngsters who were soon to enter Primary 7 were appointed and a consultant was brought in to train them in mediation skills.
Depute headteacher Anne Healey explains: "The children learned about confidentiality (not blaming or taking sides), listening to the views of others, helping them find mutually acceptable solutions to problems. The consultant came back in September for a further training session with the mediators and also worked with school staff on mediation skills."
At breaks and lunchtimes the pair of mediators on duty sit on stools looking out on the playground from their bright little office, which the parent-teacher association has decorated in reds and yellows, and consulting with a succession of troubled and sometimes troublesome clients.
It is a serious business, explains Simone Catterson, even if it might not always seem so. "The reasons people have fallen out might sometimes seem a bit silly but it would be hurtful to tell them that. So you always try to help them sort out their problems. And you never laugh."
Peer mediation has become an accepted feature of the school, valued by the pupils for the support and guidance it provides and by the staff for its influence on ethos and behaviour.
"One of the big gains," says headteacher Patricia Kennedy, "is that my teachers and I no longer have queues of kids at our doors, waiting for us to sort out who's fallen out with whom and why."
Crucially, the scheme is self-sustaining. This year's mediators - 14 were chosen from more than 30 applicants - were interviewed and trained by last year's, the skilled veterans of hundreds of mended friendships and resolved conflicts. This process benefits both the selection and training of recruits, because mediators get to know other pupils' personalities.
"Last year the mediators were chosen by interview alone and we had a couple who really couldn't get the hang of it," says Ms Healey. "But this year the children could say 'Well, she seemed good at interview but we know she's not good at listening to people'."
The right temperament and a willingness to see the world from other points of view is important for mediation.
"I used to get quite frustrated when someone wouldn't do things my way," says Erin. "But now I realise maybe it wasn't right for them. And anyway, you can't always have your own way."
Role-playing features prominently in the training, with experienced mediators modelling techniques and approaches and the recruits trying them out.
Mediators offer suggestions and encourage people to talk. They do not take sides or tell them what to do, explains Gavin Corr.
"Your job is to listen to the problem, then give examples of what they might do next. Then the two children work out their solution from there," he says.
Trained classroom assistants are always available as mentors, should the mediators need adult guidance. Urgent issues are taken to the depute headteacher.
One of the big surprises for most teachers at the school, including Ms Healey, is how much responsibility the children are willing and able to assume.
"This year's mediators are quieter than last, but they just quietly get on with it. They hardly ever have to come to me," says Ms Healey. "One of the girls, Rebecca O'Hara, even volunteered to organise the rota, which is quite complicated, so I no longer need to do even that.
"Basically, the youngsters are running it themselves. I've been amazed at how well they do the job and at the difference it has made to the school."
Ms Kennedy is convinced of the benefits of peer mediation, on the school, on the younger pupils and on the mediators themselves. "At St Mark's, our children are very well taken care of, so when they get to Primary 7 this is a way for them to give something back. We tell them they are helping us to run the school."