The incidence of Autism (or its identification) seems to be increasing. People want to KNOW what are the underpinnings or contributors and can it be prevented. Every year more studies reports are adding to the body of knowledge. Two main theories are being investigated: Anatomical and psychological. (Poor upbringing per se has pretty well been discounted.) Genetic dysfunction and possibly mirror neurons may be the most promising path.
Rather than try to restate the abstracts, I will share some study URLs or reports that seem to be whittling away at this bit by bit. You can try to access them directly if you are interested. Currently they are all functioning. However, sometimes the addresses are changed or removed, as you know.