Some symptoms of mild autism are obsessive behavior, delayed speech and unusual reactions to stimuli such as sights and sounds. Those with mild autism sometimes prefer to play or be alone, do not understand personal space and avoid eye contact, according to the Centers for Disease Control and Prevention.
A young child with autism may exhibit symptoms like not responding to his name, not playing pretend and not interacting with people or emulating sounds by 12 months. By 12 months, most children complete gestures such as clapping or waving and find people's faces and social games interesting. While failure to do these things does not automatically mean autism, these are typical early warning signs, explains the CDC.
Self-stimulating and soothing behaviors, such as rocking, arm flapping and spinning, is also common in peoplee with autism. Many people with autism have different methods of communication and do not always understand tone, sarcasm and jokes, advises the CDC. People with autism often crave routine and do not always handle changes well.
Because people with autism display a wide variety of symptoms and the disorder manifests itself in many ways, people concerned that they or their children have autism should consult specialists, according to the CDC.