Cognitive biases screw up everyone’s thinking. They make us more afraid of flying than driving. They stop the U.S. enacting universal health care. And they convinced Tony Blair and George W. Bush that the Iraq War was a great idea, even when we knew it wasn’t. In short, cognitive biases make us less logical, less rational and less efficient decision makers. All of this applies to teachers too. Here are five cognitive biases that screw up your thinking in the classroom and why they stop you from being a better teacher.