A rubber glove and two paintbrushes are all you need for this experiment. It’s easy to do, but the result can be quite unnerving.
Put a stuffed rubber glove on the table, and place the same hand (left or right) out of your sight. Put it either under the table or behind a screen. The closer you can get it either alongside or underneath the glove without being seen the more successful the experiment will be.
Now ask a friend to stroke your hand and the rubber glove at the same time, using the paintbrushes. The more the stroking is synchronised the stronger the effect is. After a little time something quite unnerving will happen – it will start to feel as if the rubber glove is part of your body.
Even though rationally you know that the glove isn’t part of your body that won’t stop you feeling that it is. This even extends to trying to flinch, or pull the rubber hand away, when someone makes to stab it with a knife. The illusion is that strong.
It’s not just a mental effect either. The actual left hand starts to see its blood flow decrease and its temperature drops. The rest of the body starts to react to the actual left hand as if it isn’t a really part of the body.
This experiment demonstrates the strength of our brain’s body mapping ability, and how it can be compromised. It’s this body mapping that lies behind the pain of phantom limbs, and the condition known as Body Identity Integrity Disorder.
If you found this rubber glove experiment interesting why not read about one with three buckets of water. Or why not sign up for my monthly newsletter here with three stories every month on the quirky side of psychology and relationships.