Book excerpt: An introduction to the science behind stereotypes. From the time we’re babies, our brains sort and label the world around us — a necessary skill for survival. But there’s a downside: we also do it to groups of people in ways that can be harmful. With loads of examples, here’s a scientific overview of stereotyping, covering the history of identifying stereotypes, secret biases in our brains, how stereotypes affect our sense of self, and current research into the ways that science can help us overcome them. Adolescents are all too familiar with stereotypes. Here’s why our brains create stereotypes, and how science can help us do it less.