When pioneering developmental psychologist Professor Uta Frith started her training back in the 1960s, she met a group of beautiful, bright-eyed young children who seemed completely detached from the rest of the world. It turned out they had just been given the then-new diagnosis of autism. Uta passionately wanted to know more about these children, and they inspired her to dedicate the rest of her career to studying the autistic mind. On the eve of National Autism Day, Horizon reveals how Uta's lifetime study of people with autism has transformed our understanding of this mysterious condition. In this film Uta shows how people with autism perceive and interact with the world and how, for them, another kind of reality exists. She meets people with autism who have extraordinary talents, and explains why they often fail to understand jokes. She also explores whether many of us could be just a little bit autistic.