Education: Personally speaking; Tony Mooney

'Schools should openly teach their pupils the rules of the lying game, so that it becomes as much as part of normal development as telling the truth'

Teachers have little time for politicians these days. Westminster is seen as such a pit of corruption and double standards that when our elected representatives start pontificating about the teaching of morality, teachers tend to turn a deaf ear. Those teachers who can be bothered to join in the debate rightly ask: which moral code should we be promoting, and should we be laying down hard and fast rules?

Lying, or "dissembling" as it has become known in parliamentary circles, is a case in point. Time and again we see examples of MPs lying for their own self-interest, yet we can be certain that truthfulness and honesty would be at the centre of any moral code they suggested for teaching in our schools.

However, we should not be too harsh on our politicians in the light of new psychological studies which suggest that we all lie at least once a day, and often more than that. So should teachers have to promote the idea that all lying is wrong, even when the evidence suggests that the truth on every issue is hard to deal with?

Not all lies do damage, and our society is governed by a complex set of principles that determine which lies are permissible and which are not. Children begin to learn this from a very early age.

What schools need to do is openly to teach their pupils the rules of the lying game, so that it becomes as much a part of normal development as telling the truth. We need to help children to distinguish between acceptable, "white" lies and those which damage the credibility of individuals and hurt them in consequence.

Children are subjected to acceptable lies from a very early age. Their parents lie about the existence of Father Christmas and the Tooth Fairy. Dentists lie to children about the non-existence of needles and injections for numbing pain. These lies are always found out at some stage, presumably without damage to those who have been told them. But if teachers start to question this natural order of things there could be friction between families and school.

The research into lying suggests that we all lie to maintain good relations with other people. Bella DePaulo and her colleagues at the University of Virginia and Texas A and M University have shown that most of the lies that we tell arise because of our need to enhance our status, to protect ourselves from embarrassment or disapproval, or to prevent arguments. A quarter of the lies we tell are to protect the feelings of others.

Children often observe adults telling lies to good effect, to protect others. They hear their parents telling friends that they like a new item of clothing they may be wearing, and then quietly saying the opposite when the friend has left. Under similar circumstances children observe adults telling acceptable lies about the appearance and health of friends and acquaintances. Seriously ill friends are often caught up in a web of self-deception spun by their friends who tell them they look reasonably well when, in fact, they look and feel awful. Such lies are acceptable because we all know that most people who are suffering from ill-health are grateful to hear some words of encouragement.

There is a danger in being too dogmatic when we teach our children about morals. Lying highlights this point because children see too many everyday examples of the benefits of not telling the truth. They see that the most skilful liars are often highly successful in relationships, work and politics.

If schools take too intolerant a stance on lying they can exacerbate the problem. A hard line on lying often forces children to be more dishonest, not less. Punishing them too severely for lying makes it more likely that they will become more adept in their lying to escape further punishment. So what teachers need to do in their schools is create a social climate in which pupils can tell the truth about their misdemeanours without getting into so much troublen

The author is headteacher of a comprehensive school in south London writing in a personal capacity