The chemistry in each class is different. Fortunately, most work harmoniously together, but occasionally one group will not cohere and hard work is needed, so start by involving the children themselves. Try questions such as "What do we need to do to make sure everything goes well when we work in groups?", or "Why do you think children sometimes fall out with each other?" Discuss these with the whole class, in pairs or small groups, or with individuals. They are fundamental questions about human relationships and learning, perfectly legitimate parts of a programme on citizenship, or personal and social education, provided they do not become too self-indulgent.
If something still goes wrong, remind those concerned of what the class previously concluded about harmonious working.
Try activities that require harmony and co-operation (for example, working in teams to produce a newspaper, or a TVradio programme) and be up front about how important it will be to help each other, for everyone to have a role as reporter, writer, producer, announcer, or whatever, not to hog things, to encourage, to work as a team. Then praise them to the skies, as a class, for doing it so well and exhibit the results to a wider audience, especially one including parents.
If you are really brave (because they might criticise you), ask them to write a piece in two sections called "What I like and what I don't like about being in this class". Some results might be bland, but others could be illuminating about the process as seen through the eyes of children themselves. If all else fails, you may need to use the "Look here, sunshine" approach and tackle it head on - but save that for last.
Try a bit of Tuckman
I get the feeling that mixed-age classes are not a long-standing tradition in your school. So it has probably come about either because of falling rolls or because of funding changes, and parents will almost certainly see this as "a bad thing", with all sorts of misconceptions about children doing the same year's work twice. This will spill over to the children, who will have their own feelings; Year 6 particularly may feel they are being denied the opportunity to be the "top class".
A group dynamics theorist called Bruce Tuckman has argued that groups go through four stages: "forming", when the group are being nice to each other because they are new to each other; "storming", when they argue and fall out; "norming", when the class starts to settle down and establish a "pecking order"; and, finally, when they have gelled, "performing", when they start working as group. Your class are probably at the storming stage, and things should improve.
Start a project that will enthuse the class and make them feel like a single entity. Then hold an open afternoon for parents to show them the work your class has done on the project. During the afternoon, as well as showing the project, do a great PR job on the benefits of the mixed-age class.
Liz Parkinson, Stockport
Make a fresh start
There's no reason at all why mixed ages shouldn't work well together. I suspect the groups have been recently amalgamated or, even more likely, they've recently been taught by a teacher who wasn't much good.
Look in any well-run classroom and you'll find a charismatic teacher at its centre. Hopefully, you're like that too, and it's the best possible starting point. When parents appear telling you they don't want Simon sitting anywhere near Sheila, give a beaming smile, say you're starting afresh, and point out that everybody is going to work really hard on getting along with everybody else.
Then put all your efforts into the classroom. Organise seating carefully, establish clearly defined rules of behaviour, gradually make the room into an attractive environment that the children can be proud of, and show that you really care about all of them.
Keep away from the group or paired work for a time. It's a chance for you to show your skills as a lively, inventive teacher with whole-class work.
Primary head, East Sussex
Coming up: Infants are being exposed to unsuitable films
"I teach reception children who regularly tell me the plots of movies - including the Terminator series - that I wouldn't let my own children of 11 and 12 watch. Should I keep quiet or discuss this with their parents?" What do readers think? Email email@example.com