My theory was based on empiric observation of a few people I know and was that females generally put toilet rolls on with the paper hanging down the wall and men generall put them on with the paper hanging away from the wall. I formed this after living with someone who was female and enforced this stereotypical behaviour. Behaviour which seemed completely illogical to me because it is more difficult to use when the paper is down the wall. As I don't use patterned toilet paper that hadn't been something about which I had thought.
Anyway the results - thanks everyone - show that 6 females do (or have for a large part of their lives or until converted) indeed hang the paper down the wall. Significantly no males hang it that way. On the other hand 6 males responded (or were mentioned in despatches) and all hung it away from the wall. Having said that 10 females hang it away from the wall or have been converted to seeing the light.
So the conclusion simply shows that the general consensus is that hanging it away from the wall is the way to do it. Ah well. men have to be able to get something right!