However many lies we tell, the truth comes out eventually. With this in mind, why not get pupils to think about how truthful they are with an assembly?
More than 400 years ago, William Shakespeare wrote in The Merchant of Venice:
"Truth will come to light; murder cannot be hid long; a man's son may, but in the end truth will out."
We still use the phrase "truth will out" today. We read exposes in newspapers and see lies exposed on TV. Discuss with pupils how people all around us tell lies. Some politicians lie about what they will do for the country if elected. Film stars lie about their relationships. Footballers lie about unfair tackles. People lie about taking things that do not belong to them. Can they think of any examples? Explain how hiding the truth can lead to serious consequences.
A good example to use here is a recent storyline on EastEnders. Viewers waited for weeks to find out the identity of Amy's father - is it Sean or Jack? We saw her mother Roxy taking a DNA sample from Sean as he slept, then we knew that she had got the results and lost them, only for him to find them later and the truth that he was not the father to come to light. Ask pupils, would the outcome have been different if Roxy had told Sean about the DNA test before the truth came out? You could use clips from YouTube to illustrate the dilemma.
As well as lying to other people, we also lie about who we are. Sometimes we are tempted to tell lies about ourselves and our families, perhaps to impress others, perhaps to gain friends - but what happens when the truth is out? Your pupils will probably be familiar with the Disney film Camp Rock that came out last September. When the lead character Mitchie first finds out that she is able to attend Camp Rock, a summer camp devoted to music, she is overjoyed. Her mum has been hired to do the catering and as a result Mitchie gets into the camp at a reduced rate, as long as she agrees to help in the kitchen.
Mitchie is overwhelmed by the famous parents and amount of money the other children seem to have. She is ashamed of her parents and lies to fit in. She claims that her mum is the managing director of successful company Hot Tunes China. And once the lie is told, there is no going back. Even when her mum comes to introduce herself to her friends, she doesn't admit the truth, but dismisses her as someone who has cooked for the stars.
As Shakespeare said, truth will out. When her friend Caitlyn discovers the truth and describes her as drowning in her lies, Mitchie justifies herself by saying: "I just wanted to fit in, OK?"
But it's not OK. When the camp diva Tess Tyler finds out, she humiliates Mitchie and exposes her lies. Mitchie learns the hard way that it's not all about image, but allowing people to see who you really are.
You could conclude that, just like Mitchie, we can get so caught up in our lies, so trapped by our deceit. But we don't have to lie about who we are, or what our family is like, or what we have. Our real friends will accept us just as we are. And then, like Mitchie, we can find the freedom to be ourselves by telling the truth.
For this and more assemblies see www.assemblies.org.uk.