Brain & Nervous System Guide to Autism Symptoms Common Behaviors That Characterize Autism Hallmark features include difficulties with social interaction By Vincent Iannelli, MD facebook Vincent Iannelli, MD, is a board-certified pediatrician and fellow of the American Academy of Pediatrics. Dr. Iannelli has cared for children for more than 20 years. Learn about our editorial process Vincent Iannelli, MD Medically reviewed by Medically reviewed by Steven Gans, MD on September 25, 2019 Steven Gans, MD, is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital. Learn about our Medical Review Board Steven Gans, MD Updated on January 10, 2020 Print There are distinctive behaviors that characterize autism. Autistic children have difficulties with social interaction and communication, problems with nonverbal communication, and repetitive behaviors or narrow, obsessive interests. These behaviors can range in impact from mild to severely disabling. Delphin E Le Berre / Moment / Getty Images Impaired Social Interactions The hallmark feature of autism is impaired social interaction. Parents are usually the first to notice symptoms of autism in their child. As early as infancy, a baby with autism may be unresponsive to people or focus intently on one item to the exclusion of others for long periods of time. A child with autism may appear to develop normally and then withdraw and become indifferent to social engagement. Children with autism may fail to respond to their name 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 have trouble showing empathy. How Autism May Affect Sympathy and Empathy Repetitive and Restrictive Behaviors Many children with autism 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 autism 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. Understanding Why Your Autistic Child Rocks, Flaps, and Paces Sensitivity to Sensory Stimulation Many children with autism have a reduced sensitivity to some stimuli like pain but may be abnormally sensitive to sound, touch, or other sensory stimulation. These unusual reactions may contribute to behavioral symptoms such as a resistance to being cuddled or hugged. Autism and Sensory Overload Children with autism appear to have a higher than normal risk for certain co-existing conditions, including fragile X syndrome (which causes mental retardation), tuberous sclerosis (in which tumors grow in the brain), epileptic seizures, Tourette syndrome, learning disabilities, and attention deficit disorder. For reasons that are still unclear, about 20 to 30 percent of children with autism develop epilepsy by the time they reach adulthood. While people with schizophrenia may show some autistic-like behavior, their symptoms usually do not appear until the late teens or early adulthood. Most people with schizophrenia also have hallucinations and delusions, which are not found in autism. Was this page helpful? Thanks for your feedback! Sign up for our Health Tip of the Day newsletter, and receive daily tips that will help you live your healthiest life. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Posar A, Visconti P. Sensory abnormalities in children with autism spectrum disorder. J Pediatr (Rio J). 2018 Jul - Aug;94(4):342-350. doi: 10.1016/j.jped.2017.08.008 Additional Reading National Institute of Neurological Disorders and Stroke. Autism spectrum disorder fact sheet. Updated August 13, 2019.