Well, the problem is, how would they know? I wonder if they can differentiate between their own thoughts and their twin's thoughts - they could all just pop into both of their heads, just like a "natural" thought. Also, I'm not sure if they would understand the difference, since they've never experienced anything else to compare it to.
You seperate the two's sensory perception as far as possible (blindfold, ear plug, make sure they can't touch), tell one to think of something, and ask the other about it?
I think they share sensory perception, it was mentioned that tickling one will make the other laugh, and a few other things. If one imagines something, though, I'm not sure if the other receives it. Could possibly be that sensory input is doubled, but we don't know about generating thoughts.
Also - what would it be like to see from two sets of eyes?!
Bizarre?? Sorry to keep chaining replies, but it got me thinking... what happens when one sleeps and the other is awake? You could try that! Presumably the asleep one can't 'listen in'. Just tell the awake one to think of something when the other awakes (but dont say anything about it), and then ask the other!
Hell, what happens when one dreams while the other is awake! INCEPTION.
Can one sleep without the other also sleeping? That would be an interesting input into the "are they one or two people" questions (FWIW, I think they are two, from my limited information).
> what would it be like to see from two sets of eyes?!
Obviously, this is pure speculation but in the same way that we can fuse the signals from two eyes into one coherent image, I don't see why, in principle, the brain couldn't fuse the signals from four eyes into one image.
