How can I tell if my child has autism?

In infancy? Core symptoms of autism look different at different ages, but always include delays in social communication. A 4-month-should goo and coo " in sync" with mom, a 6-month-old should raise his arms to be picked up, a 9-month old should respond to his name. The diagnosis includes much more, but these are things parents can notice early. Firstsigns.Org has good checklists for parents. Check it out!