Signs of Autism Checklist Early Childhood, Primary Years, Teens & Adults - Autism Awareness - Signs, Symptoms and Characteristics of AutismFrom birth to 2 years of age is a high growth period in development, recognising autistic characteristics during this age range can be difficult, for some people their autism characteristics don’t become apparent until later - school age, high school or even as adults. However, there are certain characteristics that parents can look for in the first years