A study published on 26 August in the journal iScience indicates that our sense of who we are has to do not only with our environment and life experiences, but also with our bodies.
The study showed that “swapping bodies” with a close friend in a perceptual illusion shifts our beliefs about our own personality to more closely match our beliefs about the character traits of the other person.
“As a child, I liked to imagine what it would be like to one day wake up in someone else’s body,” said first author Pawel Tacikowski from the Karolinska Institutet in Sweden. “Many kids probably have those fantasies, and I guess I’ve never grown out of it – I just turned it into my job.”
In the experiment, researchers outfitted pairs of friends with goggles showing live feeds of the other person’s body from a first-person perspective and applied simultaneous touches on both participants’ corresponding body parts to make the illusion stronger.
The effectiveness of the illusion, which typically kicked in mere moments after induction, was demonstrated when the researchers threatened the friend’s body with a prop knife, resulting in the other person breaking out in a sweat.
Prior to the “swap”, participants rated the personalities of their friends on several dimensions. Later, during the intervention itself, they were asked to rate their own personalities, which showed that, while “inhabiting” a friend’s body, they tended to perceive themselves as more similar to their friends than otherwise.
Furthermore, participants who felt more identified with their friend’s body also did better on memory tests, which indicates less “self-incoherence”, i.e., the disconnect between one’s mental and physical self-representation. Under normal conditions, people are usually better at remembering things related to themselves.
Given how quickly people’s self-concept changed in response to the illusion, Tacikowski claims that these findings could have implications for future research on, and treatments of, depersonalisation disorder and other mental disorders, such as depression.
“People who suffer from depression often have very rigid and negative beliefs about themselves that can be devastating to their everyday functioning. If you change this illusion slightly, it could potentially make those beliefs less rigid and less negative.”
Before the technique is applied in people suffering from debilitating mental conditions, however, Tacikowski plans to conduct more work necessary to establish how the sense of self is constructed across the body and mind.
“Now, my mind is occupied with the question of how this behavioural effect works – what the brain mechanism is,” Tacikowski said. “Then, we can use this model for more specific clinical applications to possibly develop better treatments.”sw