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.

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.

In autism there is just genes in part more or less of a probability that you will have the disorder, and that is where interactions with the environment are key.

I think my own bias is that there may be something wrong with the timing and the connectivity between regions rather than pointing to one particular spot in the brain.

The brain immediately confronts us with its great complexity. The human brain weighs only three to four pounds but contains about 100 billion neurons. Although that extraordinary number is of the same order of magnitude as the number of stars in the Milky Way, it cannot account for the complexity of the brain. The liver probably contains 100 million cells, but 1,000 livers do not add up to a rich inner life.

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.