Lisa Simpson is a fictional character on the American television show The Simpsons. As the brainy younger sister of the ultra-cool Bart Simpson, she can appear to have qualities of people with autism. She does not fit in well with her peers, and often speaks more like an adult than a child. However, she is also capable of empathy, as evidenced by the episode where she gave a Valentine to the only boy in class who did not receive any cards at the class party. It is likely that Lisa is just a gifted, precocious girl.