with other kids at school and this may help the child socially. However, I want to direct the autistic child's interests into more constructive activities.
Genetics and Autism
Research during the last ten years confirms that autism, PDD, and Asperger's all have a strong genetic basis. Craig Newschaffer, Johns Hopkins School of Medicine, estimates that 60 to 90 percent of autism cases are genetic. Dr. Isabel Rapin and her colleagues at Albert Einstein College of Medicine reviewed papers published between 1961 and 2003. They concluded that interactions between multiple genes explain the highly variable nature of autism. Genome scans of families with many cases of autism indicate that at least ten genes are involved. They also found that the probability of having a second autistic child is 2 to 8 percent. Researchers have also confirmed previous studies that show that relatives of people with autism will often have many milder autistic-like symptoms. I have observed that the probability of having a child with low-functioning autism increases when both parents and their families have many autistic traits.
Many computer programmers exhibit autistic traits. Steve Silberman asked in an article entitled «The Geek Syndrome» in Wired magazine — are math and tech genes to blame? The computer and technical industries depend on people with attention to detail. The real social people are not interested in computers. Herbert Schreir of the Children's Hospital in Oakland, California, believes that intermarriage of «techies» explains why people have noticed high pockets of autism around Stanford and MIT Universities.
In 2004 and 2005, my webmaster for www.grandin.com (my livestock website) started giving me a list every month of the cities with the most hits on my webpage. Month after month, Redmond, Washington, where Microsoft is located and San Mateo, California, near Stanford University are in my top five cities. There is a total of one hundred cities on the list. The number one page downloaded is the first chapter of Thinking in Pictures. Even though my site is a livestock site, the autism book chapter gets the heaviest traffic. Is this because people in these areas are especially interested in the ways brains work, or does autism affect them more directly?
There are differences of opinion in the autism field about the relationship between autism and Asperger's. Are they really separate syndromes? Family and genetic studies done in the United Kingdom indicate that autism and Asperger's are part of the same spectrum. Research by Fred Volkmar at Yale showed that Asperger individuals with no speech delay are often poor at a visual thinking task such as the block design test on the WISC and high- functioning autistic individuals are more likely to be good at this test. In the block design test, the task is to assemble colored blocks to match patterns shown in a book. This difference could be explained by the differences in where the «computer cables» hook up. The underlying brain abnormality of underconnectivity problems would still be similar.
There is concern among people with Asperger's that genetic testing could eliminate them. This would be a terrible price to pay. Many gifted and talented people could be wiped out. A little bit of autism genetics may provide an advantage though too much creates a low-functioning, nonverbal individual. The development of genetic tests for autism will be extremely controversial.
Autism Epidemic
Many researchers agree that the increase in Asperger's syndrome is mostly increased detection. People who used to be labeled as science geeks or computer nerds are now diagnosed with Asperger's. Research in Sweden by Christopher Gillberg showed that some severe cases that used to be labeled mentally retarded are now labeled autistic. Another cause of the increase may be changes made to the DSMIV (Diagnostic and Statistical Manual) published by the American Psychiatric Association in 1994 to expand the diagnostic criteria to include Asperger's and Pervasive Developmental Disorders (PDD). The Centers for Disease Control (CDC) estimate that there are three to four autism cases per one thousand children. A CDC study in Atlanta, Georgia, indicated that 40 percent of all children on the spectrum are only diagnosed at school and 41 percent of special education students are on the autism spectrum. A fully verbal child with mild Asperger's will often not have any problems until he/she enrolls in school. Unfortunately there are severe cases of autism who do not receive services until they go to school. From my own observations there is one type of autism that I think has increased. The regressive type where the child loses language at age eighteen to twenty-four months. David Geier and Mark Geir, two autism consultants, state that exposure to mercury causes regression-type autism. Mercury has now been removed from many vaccines, but fish and power plant emissions are other sources of mercury. Other scientists question the effect of mercury in the incidence of autism.
There is increasing concern about environmental effects on the fetus during pregnancy. If these factors affect the incidence of autism, they probably could interact with susceptible genetics. An outside insult like toxic exposure could turn a brilliant Asperger baby into a nonverbal one. This is purely speculation. New research supports the idea that genetics susceptibility interacts with environmental insults. Scientists have developed a genetic line of mice that are highly susceptible to mercury toxicity. When the mice are given injections that mimic a vaccination schedule the normal mice have no ill effects and the susceptible mice develop autistic-like symptoms such as tail chewing and repetitive behaviors. Possibly there are some children who would have a similar susceptibility to mercury. Mady Horning at the Columbia University School of Public Health has a three-strikes model. The factors that all interact with each other to cause a developmental disability are:
1. Genetic susceptibility
2. Exposure to a toxic agent
3. The timing during development that exposure to a toxic agent occurs. A toxic agent may have no effect at one stage of development and bad effects at another stage.
Twin studies show further evidence of an interaction between environment and genetics. Mady Horning states that the concordance rate for autism in genetically identical twins is 90 percent. This means that 90 percent of the time both twins are autistic. In genetically different nonidentical twins the concordance rate is 35 percent and the autism rate in siblings is 4 percent. Further information on the mercury controversy can be found at the Autism Research Institute in San Diego, California, or in a new book by David Kirby entitled Evidence of Harm.
3
The squeeze machine
From as far back as I can remember, I always hated to be hugged. I wanted to experience the good feeling of being hugged, but it was just too overwhelming. It was like a great, all-engulfing tidal wave of stimulation, and I reacted like a wild animal. Being touched triggered flight; it flipped my circuit breaker. I was overloaded and would have to escape, often by jerking away suddenly.
Many autistic children crave pressure stimulation even though they cannot tolerate being touched. It is much easier for a person with autism to tolerate touch if he or she initiates it. When touched unexpectedly, we usually withdraw, because our nervous system does not have time to process the sensation. One autistic woman told me that she enjoys touch, but she needs to initiate it in order to have time to feel it. Parents used to report that their autistic children loved to crawl under mattresses and wrap up in blankets or wedge themselves in tight places, long before anyone made sense of this strange behavior.
I was one of these pressure seekers. When I was six, I would wrap myself up in blankets and get under sofa cushions, because the pressure was relaxing. I used to daydream for hours in elementary school about constructing
