Autism is a developmental disability that significantly affects verbal and nonverbal communication, social interaction, and educational performance. It was first described in the 1940s and research continues today to study autism since its causes are unknown, though abnormalities in brain structure/function and genetic/environmental factors may play a role. Characteristics of autism include difficulties with social skills, communication, and resistance to change. Effective teaching strategies involve creating structured and predictable classrooms, promoting social skills, and using visual aids to communicate with students.