This is a segment shown on the PBS Newshour Jan. 19, 2016. It provides an excellent history of public awareness and understanding (and misunderstanding) of the causes of Autism. In a nutshell, the author believes that autism in its full spectrum has always been a disability within our population and is not something new caused by environmental toxins. The increases in numbers is due to a greater understanding of all the possible variations within the spectrum that has lead to greater identification. The video is eight minutes 13 seconds long and worth watching. I plan to check out his book as well.