How many children leave school with their teacher's political opinions? An often told joke made by Right-wingers who were rather more Left-wing in their youth is that young people on the Right have no heart, while old people on the Left have no head. In her brilliant article today Carola Binney, an 18-year-old politics student, not only articulately rebuts the main premise of the joke - that Conservatism is for the heartless - she also shows how, very worryingly, it's an idea which seems to be informing politics teaching in this country. Of course curricula, syllabuses and mark schemes will always be a source of controversy, particularly in subjects like history and politics. As a historian I saw first-hand just how heated the debate can get about what's included, and just as significantly, what gets left out. In many ways those designing a syllabus for history and politics face the same challenge. Both subjects can have a significant impact on how our children see the world, which will help define their politics as they grow up. Taught well, pupils will have the chance to make their own minds up, with a richer understanding of their own beliefs than they started with. Taught badly though, with the evaluation done for them, they leave children with a distorted worldview based on the opinions of others. The effects of this are long-lasting. In truth voters only very rarely change their party of choice, making it all the more worrying that there seems to be such a significant Left-wing bias in the way that politics is examined. When in polls the Conservatives invariably beat the Labour party on economic competence it is completely unacceptable to trot out the Labour line opposing deficit reduction and then give eight points in the mark scheme supporting it with only one in opposition. There is no doubt that politics teachers, who will often have passionately-held views of their own, have a difficult job. It's much harder to be unbiased than it is to speak your mind. Yet it is vital that they are able to put their views aside. For every Carola Binney, who sees the bias for what it is, who knows how many are leaving school with someone else's political opinions. We need to put this bias right, and not just out of a sense of political fairness. Much more importantly it's about respecting the opinions of these politics students who will grow to be some of the most engaged citizens in Britain, with many no doubt going on to work in government or seek election. We owe it to these pupils not to burden them with any of the political prejudices of our generation, and to give them the chance to make their minds up for themselves. Chris Skidmore is MP for Kingswood and a member of the education select committee