There are a quite number of ways to see the physical characteristics of Autism in children. The autistic kids do not say a single word till they are 16 months old. They do not say combined words or for small sentences till they are 2 years old. They do not even respond when their names are called by their parents. They do not prefer to be cuddled since they tend to get physically hurt in this process. They do not take interest in toys like the other kids.
The autistic kids do not like to be exposed to bright lights of loud sounds. They get very irritated by it and tend to cry profusely. They just like to sit in a corner and get lost in their own thoughts. They do not want to be interrupted. They could take a object of their own obsession and keep staring at it. They also like to arrange their things in a particular pattern of their choice and would react violently if anyone disturbs their pattern.
The autistic kids like to do repeated physical actions like flapping their hands or repeating some words or sentences. They do not have a proper body balance and like walk on their toes. They sometimes even run in circles. Most of the time they tend to hurt themselves by doing this. They do not appreciate socializing since they are unaware on how to react to the social stimulus. They do not like being touched and would get physically hurt easily.
They look normal like any other people but they react in a way which not natural. They might have good IQ and would excel in their field. They can go on and on about the topic of their interests and would not like it if they are interrupted. Their habit of monologue would normally bore their listeners.
The people with autism are very normal in their appearance but they have the habit of repeating their normal life actions. They would prefer to eat the same type of food every time and even try and wear the same type of cloths. They normal life patterns almost result in become cycles of their lives.
However, we get see a lot of examples where people have learnt to cope up with this disorder and then go on to become famous in their life in their won fields. Proper parenting and understanding these kids and giving them proper medication at the right time is an absolute essential aspect to make this happen.