What is a primary sign of autism?

Impaired social interactions are a primary sign of autism spectrum disorder (ASD). Individuals with autism often struggle with understanding social cues, maintaining eye contact, sharing interests or emotions with others, and engaging in typical back-and-forth conversations. This core feature significantly impacts their ability to establish relationships and communicate effectively with peers.

While high verbal ability can be present in some individuals with autism, it is not universally indicative of the disorder, as many may have delayed speech or language challenges. Excessive physical activity is not specifically associated with autism and can be found in a variety of behavioral contexts, including normal child development. Unusual sensory perceptions, although commonly reported among those with autism, are part of the broader sensory processing challenges that could also be seen in other conditions. Therefore, the defining characteristic of impaired social interactions stands out as a central feature of autism.