As pupils, we are led to believe that our teachers want the best for us. We might not be their favourite and we might not be the brightest, but if we work hard, learn what we are told to learn, read what we are told to read, revise for our exams and, above all - according to teachers - pay attention in class, we should do alright.

“Fulfilling your potential” and “do your best” are buzz phrases. If pupils had pound;1 for every time they heard, “It’s for your future” or “It’s for you not me - after all I’ve got my GCSEs”, they would be rich enough not to worry about succeeding at school in the first place.

But some teachers, while wanting the children they teach to do well, want their own children to do better. And although their schools and their teaching methods may be alright for other people’s children, they are not good enough for their own.

I noticed this recently while speaking to a comprehensive school teacher I know.

She was talking about having visited school open days despite her daughter being just a year old.

She needed to know which primary her daughter would attend so she could send her to the right nursery, as one fed into the other and both ultimately fed into particular secondaries.

These were private schools, of course. I queried why her daughter would not be going to the local state school, or the one where she herself taught.

“If you had seen the school I work in,” she said, “you wouldn’t want to send your child there either.”

What this teacher was effectively saying was that her “bad” school was good enough for other people’s kids but not good enough for her own.

In other words, she was saying “I don’t want my child to be taught by a teacher as bad as me.”

If she believes she and her colleagues are not bad teachers, she should have no problem with her child being taught by people like them.

Or it may not be the teachers she has a problem with but the children.

Perhaps she does not want her daughter to go to a school like hers because she does not want her to mix with children who are “not of the right type” - that is, whose parents are not rich enough to pay for their education.

This is even worse: I don’t want snobs teaching in state schools, or people who think there are children who are “the right type” and those who are not. I want children to be taught by people who truly believe that all children deserve the best education possible and equal access to opportunities.

I believe in the comprehensive ideal, and what’s more I believe teachers in comprehensive schools should believe in it, too. And of course to be truly comprehensive means to have children from all backgrounds, including the children of teachers.

This is not to say, of course, that it is necessarily right to send your child to the actual school you teach in, although in rural areas in particular this can be hard to avoid.

I know of teachers who teach in the school they attended as children, where their parents also taught, and who are likely to send their own children there, too.

This not only limits their experience of the world, but suggests they have a particularly insular way of looking at things.

But I think teachers need to be advocates of the system in which they teach. After all, you wouldn’t fly in a plane designed by an engineer who refused to travel in it, would you?

And one of my favourite questions to ask people, be it doctors or builders, when I am dithering over what course of action to take, is: what would you do if it was your heartgrandmotherfloorboards (delete as applicable)?

It is like the parent I know who recently moved to a county where the 11- plus is still used because he wanted his toddler to be able to go to “a good school”.

It is mean of me, but I rather hope that when the time comes this child fails the 11-plus, just so the parent sees the folly of their action and wishes instead that they had moved into an area where schools were good for all children, not just the clever ones.

Then there is the man I know who was a governor of a local state school, but sent his child to a private school some distance away because he felt “it would suit her personality better”.

Perhaps it would have better suited the personalities of the children in the school where he was governor if they had enjoyed that opportunity, too. But they didn’t.

No doubt this man did commendable work as a governor, both for the good of the school and to ease his guilty feelings over his double standards.

But had more children of governors and teachers been pupils there I suspect he would have had even more incentive to improve the state system rather than just using it to salve his own conscience.

All teachers know they do not just teach their own subject. In a school environment they are a responsible adult who should show, by example, key character traits from which pupils should learn.

These include tolerance, patience, kindness, belief in equality and a thirst for knowledge. Schools are, after all, a place where we learn a lot of our key values.

Hypocrisy, double standards and a failure to believe in what you are teaching should not be among them.

Do you agree with Elle Levenson? Email letters@tes.co.uk

• Elle Levenson, Author of `The Noughtie Girl’s Guide to Feminism’.