I have read a couple of the books by Elaine Aron and I have found them extremely useful as an HSP. I don't agree with every part of her books but I appreciate she has tried to make studying this type of thing as much of a science as can be expected. I DO buy into the fact that due to certain circumstances in the development of our nervous systems HSPs can be more attuned to stimulus than other people. I've learned too much about the development of the nervous system and how such subtle changes can affect it not to think there could be some protein or defect somewhere that resulted in a more sensitive nervous system.

Here's a link to more information on the subject if you are interested.

http://www.hsperson.com/pages/aron_bio.htm