Autism starts long before it is diagnosed at the age of three. The most distinct characteristic of autism is delay of social development. We don't know why there is social delay in autism, but we do know that if there is any barrier to touch in the first three years of life, there will be social delay. This is because touch is the most important sense for early social development. In autism, there is a barrier to touch. Children refuse touch on different parts of their body; they struggle with it; and parents end by avoiding it. It's not the parent's fault that the child refuses touch, it's an actual problem with the child's sense of touch. What should feel good to the skin, doesn't feel good (a kiss on the face is uncomfortable; causes the child to pull away). What should hurt, doesn't hurt (cuts, burns, freezing temperature). Sensory nerves in the skin are affected, and there is a problem with the sense of touch.