Child with autism usually display persistent deficits in social communication and social interaction in various contexts, like they might have deficits in social-emotional reciprocity, deficits in the nonverbal communicative behaviors which is important for social interaction. Or might be deficits in maintaining, developing, and understanding relationships.
The also exhibit restricted, repetitive patterns of behavior, activities or interests, like stereotyped and/or repetitive motor movements, or repetitive use of objects, or speech. They insist on maintenance of sameness, they are inflexible towards adherence of routines, or practices ritualized patterns of verbal or nonverbal behavior. These children have highly restricted, fixated interests that are clearly excess in intensity or focus. These children exhibit Hyper- or hypo reactivity to sensory input or unusual interest in their sensory aspects of the environment. These disturbances are noticed in the child during the developmental days itself. The child finds it difficult meet the important developmental milestones on time.