Autism is not a snapshot. It's a life.

Autism is a developmental disorder characterized by two main components: an inability to interact socially with other people with joint attention to understand other people's thoughts.

As the diagnosis of autism is increasing the diagnosis of mental retardation is decreasing. And more and more on the other end, the high end, more children who are just a little bit off, who ordinarily you would not single out now are being described as perhaps Asperger’s syndrome or on the high end of the autism spectrum, so I don’t believe there is an epidemic.

It is not all that common, but there is a phenomenon where autism could get worse at about age two. There are some controversies whether regression is a prominent part of autism, but many people feel that it's very hard to diagnose autism before you can begin really talking in detail with a child.

There is no question there are differences between male and female brains. They are called sexual dimorphisms and you can point to different anatomical structures.

Memory is the scaffolding upon which all mental life is constructed.

I think the gold standard is a clinical diagnosis, that an astute clinician interacting with a child, interviewing the parents, talking with teachers makes the diagnosis based on some standard tests and also on clinical impression and skill.