Professor Mel Slater of the Catalan Polytechnic University has recreated the classic Milgram Experiment using a computer simulated woman, with some interesting results.

In the original experiment, conducted by Stanley Milgram in the 1960s, volunteers were told by an authority figure to deliver electric shocks to another person as punishment for incorrect answers to a test. The other person wasn’t really receiving the shocks, but the volunteers were tricked into thinking they were by shouts of pain and protest. Despite this feedback, some volunteers went on to deliver what would have been lethal shocks.

Slater’s volunteers did a similar experiment, but in an immersive virtual environment where they interacted with a virtual woman. This counters some of the ethical protests that have prevented Milgram’s experiment from being repeated because the volunteers knew they would be interacting with a virtual woman and so, unlike Milgram’s guinea-pigs, knew that nobody was being hurt.

Half the volunteers could see the woman and half could not, communicating with her only through text. Both were told to give her ‘electric shocks’ of increasing voltage when she gave incorrect answers to test questions. The woman responded to these with protests and discomfort, asking for the test to stop as the voltage was ramped up.

The group from whom the virtual woman was hidden delivered shocks up to the maximum voltage, like many of those in Milgram’s experiment. Those who could see her were more likely to stop before reaching this limit.

Almost half of those who could see the woman said afterwards that they had considered withdrawing from the study, and several actually did. “Of course, consciously everybody knows nothing is happening,” says Slater. “But some parts of the person’s perceptual system just takes it as real. Some part of the brain doesn’t know about virtual reality.”

And instead of becoming accustomed to the virtual person and ceasing to empathise, many volunteers became more anxious as the study continued. Measures of stress, such as heart rate and sweatiness of palms, increased. These measures are nearly impossible to fake, and confirmed for Slater that the volunteers were actually feeling uncomfortable, rather than performing as they thought the experimenter would expect.