https://www.jhsph.edu/news/news-releases/2020/us-autism-rates-up-10-percent-in-new-cdc-report.html Since 2000, the prevalence rate has nearly tripled, from 0.67 to 1.85 percent. I don't think you can say this is simply due to increased rate of diagnosis, because that's what they were saying in 2000. This is often a life-long disabling condition. Imagine for example Alzheimer's but it happening to children, if that helps put it in some perspective. My personal theory, I think the types of jobs required to live a middle class existence and support a family are becoming increasingly intellectual and require intense focus for long periods of time. Think about all those computer programmers in the Bay Area and Seattle. These genes appear to confer a benefit to succeed in certain type of jobs, but can also cause devastating problems in other situations. This is analogous to Sickle Cell Anemia in Africa, where the same gene that can offer resistance to malaria can also result in a fatal disease in some children. The same type of personality that succeeds as a computer programmer is also the type of mind an autistic person has. That is, natural selection evolutionary pressures within the economy are driving this, with an increased prevalence of the type of genes that can lead to disastrous consequences. I predict we will only continue to see the rate go up, in the near future.