If you could be anybody in the world, who would it be? Your neighbour or a super star? A few people have experienced what it might be like to step into the skin of another person, thanks to an unusual virtual reality（虚拟现实）device. Rikke Wahl, an actress, model and artist, was one of the participants in a body swapping experiment at the Be Another lab, a project developed by a group of artists based in Barcelona. She swapped with her partner, an actor, using a machine called The Machine to Be Another and temporarily became a man. "As I looked down, I saw my whole body as a man, dressed in my partner's pants," she said. "That's the picture I remember best."

    The set-up is relatively simple. Both users wear a virtual reality headset with a camera on the top. The video from each camera is sent to the other person, so what you see is the exact view of your partner. If she moves her arm, you see it. If you move your arm, she sees it.

    To get used to seeing another person's body without actually having control of it, participants start by raising their arms and legs very slowly, so that the other can follow along. Eventually, this kind of slow synchronised（同步的）movement becomes comfortable, and participants really start to feel as though they are living in another person's body.

    Using such technology promises to alter people's behaviour afterwards-potentially for the better. Studies have shown that virtual reality can be effective in fighting racism-the bias（偏见）that humans have against those who don't look or sound like them. Researchers at the University of Barcelona gave people a questionnaire called the Implicit Association Test, which measures the strength of people's associations between, for instance, black people and adjectives such as good, bad, athletic or awkward. Then they asked them to control the body of a dark skinned digital character using virtual reality glasses, before taking the test again. This time, the participants' bias scores were lower. The idea is that once you've "put yourself in another's shoes" you're less likely to think ill of them, because your brain has internalised the feeling of being that person.

    The creators of The Machine to Be Another hope to achieve a similar result. "At the end of body swapping, people feel like holding each other in their arms," says Arthur Pointeau, a programmer with the project. "It's a really nice way to have this kind of experience. I would really, really recommend it to everyone."