I went to a 'good' girls grammar (not in London) which became co-ed a few years after I started. It had been a college for young ladies before becoming a grammar and still had a sizeable private prep department. It was fairly mixed socially with good results overall but with quite a few low achievers- or probably more correctly bright but non-academic pupils who were put in to the lower streams. It was reportedly the best school in the area and the one where the socially astute (ie snobbish parents) wanted to go to.
I was an 11 plus entrant. My experience was mixed. There were other girls there from better off families who chose not to do any work probably because they knew they didnt have to and could walk into their parents businesses at 18. It was those girls (including the daughter of a chief police inspector) who bullied much younger girls and actually beat them up now and then and got them to sit on hot radiators until they screamed in pain and were badly burnt. They were allowed to do this because everyone else was too scared to report them or they felt that no one would believe them. The school caretaker kept some small animals as school pets. They were killed one day by some of the pupils- 4th and 5th form middle class girls- in a pretty dreadful manner. If this was in south London it would have got in the paper and the police would have been called, but at my school apart from a general dressing down in assembly it was brushed under the carpet because of who the parents were and the fact that the school didn't want the publicity.These kids were in the minority but there were enough of them to cause problems for the rest of us who knew we had to make the best of the few opportunities we had to get good results and go to university. That is now the scenario I would like to avoid my own children having to face and prefer to see a culture of respect and discipline rather than necessarily being with the ' right people'.

My view therefore of 'behaviour' is that class, background and the level of pupils intelligence are not always the best indicators of a good school experience and that a ' rotten intake' can take many forms. I regularly witness Dulwich College kids and James Allens in public and really would not want my children to be within a mile of those schools, even if we could afford it, as I just don't rate the sort of people they turn out although I suspect that thats as much down to the parents as the school, but still , its not a great advertisement.

Michaels point about school improvement partners and working with them as parents to constantly improve is very sound as this partnership is key to the success of any school. I just hope that this current government does not end up turning the clock back on education which has come a long way over the last decade or so- if anyone is interested have a look at the Local Schools Network website and join in the debate on education in the UK and current policy.