Mila Arbitman

In the Rubber Hand Illusion (RHI), participants have one of their hands out on a table (concealed) next to a rubber hand (visible). The purpose of the experiment is to create the illusion that the rubber hand belongs to the participant’s body and they feel what happens to it. Both the participants’ real hand and the rubber hand are stroked with a brush synchronously and then asynchronously to see if the participants felt the strokes even when they were only happening to the rubber hand. 

This experiment successfully tricked participants to feel what was happening to the rubber hand as if it were their own, but my mentor has found evidence suggesting the presence of demand characteristics, meaning that participants may have known that they were supposed to feel what was happening to the rubber hand, tricking them into feeling it. Demand characteristics are unintentional clues that may indicate the experiment's purpose and hypothesis, causing participants to subconsciously change their behavior. Demand characteristics affected the results of the RHI and expectancies were not matched across the experimental and control groups, so there may be a connection. The expectancies are what participants expect to feel or experience based on what they know about the experiment, meaning that participant’s expectancies may be influenced by demand characteristics. If participants have different expectancies in the experimental and control groups, comparing the results from each group may not be accurate because of how expectancies influence participant behavior. 

I will revisit different versions of the RHI to compare different control groups in order to see which matches expectancies most accurately, and see whether demand characteristics influence participants’ expectancies. My results will be relevant to all other research done on the RHI, and other psychological experiments because few match expectancies purposefully as typical clinical trials do. There is currently minimal research on how participant expectancies can impact participant behavior, so there is a possibility that many studies have been confounded by expectancies that were not matched.