From the range of people I�ve come across, the people who have the ability to speed read are generally intellectually gifted, but I suspect some of the influences may also be greater interest in topics which motivated them to read, so you�d also get �practice effect�.
In a literature search, I can skim through hundreds of abstracts potentially relevant to my profession in a few minutes to find useful references but that�s with an extensive vocabulary and wide knowledge & understanding in my fields. It�s a skill asset honed out of necessity during an extended period of time poverty but has impressed others in my workplace. Similarly, the books I read for leisure are areas in which I also have strong interest and knowledge. I wouldn�t be able to speed read content of unfamiliar topics. My husband is a radiologist, so he is well practised at viewing a large number of images simultaneously and synthesising information from everything within his visual field, so we only recently had a discussion on how he was surprised to discover that he can now �read� a page of written information at a glance which is very similar to what I do during literature searches.
Our youngest, who developed a strong interest in etymology at a young age, is the real bookworm in our family and she has true speed reading ability. She doesn�t scan pages, she reads everything chronologically and remembers it all in great detail and I am impressed with how she gets through thick novels in single sittings.
