Asperger syndrome (AS), also known as Asperger's, is a developmental disorder characterized by significant difficulties in social interaction and nonverbal communication, along with restricted and repetitive patterns of behavior and interests.[3] As a milder autism spectrum disorder (ASD), it differs from other ASDs by relatively normal language and intelligence.[6] Although not required for diagnosis, physical clumsiness and unusual use of language are common.[7][8] Signs usually begin before two years old and typically last for a person's entire life.[3]