Real Hand, Fake Hand

Our brains are way too good at adapting. Today I have a simple experiment you can try with just a friend and two rubber gloves. Have your friend wear one of the gloves and fill the the other glove in a way that it appears to be a hand. [If you happen to have a rubber arm lying around, that would work even better] Now place both the glove covered hand and rubber hand on the table. Somehow block your friend's direct line of sight to the glove covered hand. You can cover it with a sheet or place a piece cardboard in between.

Now take two of any objects, for example a brush, and touch both the rubber and real hand at the same locations. Try to keep the touches synchronized. Your friend should be able to see the rubber hand at all times. Keep this up until your friend seems really confused and or amazed. At this point, the rubber hand will feel like a real hand.

For special effects, get a third friend to suddenly stab the fake hand. Your friend will freak out and pull back his real arm.