According to the NIND, "The hallmark feature of ASD is impaired social interaction. A child’s primary caregivers are usually the first to notice signs of ASD. As early as infancy, a baby with ASD may be unresponsive to people or focus intently on one item to the exclusion of others for long periods of time. A child with ASD may appear to develop normally and then withdraw and become indifferent to social engagement.

Children with ASD may fail to respond to their names and often avoid eye contact with other people. They have difficulty interpreting what others are thinking or feeling because they can’t understand social cues, such as tone of voice or facial expressions, and don’t watch other people’s faces for clues about appropriate behavior. They lack empathy." Want to bet? Although this is true for most young children, older autistic individuals have learned many social cues and facial expressions. They do feel empathy but expressing it is difficult for them.

"Many children with ASD engage in repetitive movements such as rocking and twirling, or in self-abusive behavior such as biting or head-banging. They also tend to start speaking later than other children and may refer to themselves by name instead of “I” or “me.” Children with ASD don’t know how to play interactively with other children. Some speak in a sing-song voice about a narrow range of favorite topics, with little regard for the interests of the person to whom they are speaking" .Only in the early years. With speech programs and a supportive home environment many of these behaviors can disappear.