The other thing that strikes me is that such powers seem to be extremely culturally determined. Fads come and go in which are the most popular, mediumistic powers were very strong in the mid Victorian period but declined sharply later. In the 60s, remote viewing was a big one and it's now all but disappeared. And nowadays, whichever TV programme is popular tends to determine trends in Forteana, including psionic powers. UFOs, since the wane of the X-Files, are very much on the decline.
As someone was saying the other day, there should be more sociological studies of parapsychology to look at this kind of thing.
