Why do they lie?

It's natural to lie to get out of trouble, admits Dr Swanson. If you're not sure they've done something but suspect they have, you could say, I've heard such and such. I want to know what's happened but I'd like you to go away and think about it before you tell me the truth.

This allows them a few moments to think instead of being tempted to say immediately, I didn't do it. When they do tell you the truth, praise them for being honest.

It's more effective to make your child feel morally bad about lying than to punish him by making him tidy his room, advises Sylvia Clare. He needs to learn that lying isn't a good thing to do.

With younger children you could talk about how they would feel if a friend had lied to them. With older children you could mention items on the news where an adult has lied and been found out and been publicly humiliated. If you get angry, you're losing control, so do try to stay calm and listen.

If you have high expectations of your child you may be unwittingly making them lie to please you. For example, she may tell you she got 10 out of 10 for her maths test, only for you to discover that her book says two out of 10. If your child does anything like this, you may be pushing her too hard, so ease off.

You really do have to set a good example, says Dr Swanson. If you make a mistake and tell a white lie, say, I shouldn't have said that because now I feel guilty and that's a horrible feeling. Children will identify with that and hopefully next time, they'll think twice before fibbing.