The researchers collected photos of people of different races and Nao, a humanoid robot, and changed the color of the robot's shell to a variety of human skin tones. Their experimental setup relied on the "shooter bias" procedure, which has participants playing the role of a police officer who has to decide if they should or shouldn't shoot their gun when shown different images. Those photos had a person or Nao in it, either holding a weapon in their hand or some other, benign object. The study subjects saw the picture for only a split second and were asked to act on instinct. The study found that the participants were faster to shoot an armed black human and robot than they were to shoot their white counterparts.

An international team of researchers recently conducted a series of experiments to determine if humans are more likely to fire a weapon at a machine that's racialized as a black robot than one that looks white. Much like the doll experiments conducted by Kenneth and Mamie Clark in the 1940s, the researchers' work was designed to determine if socially inherit racial bias exists in human's perception of an object which, by its very nature, cannot actually have a race. Unfortunately, while many things have changed since then, some truly awful things haven't. In order to test how people subconsciously view racialized robots, the researchers replicated a different set of experiments designed to determine if humans have a shooting bias towards black people. They did this by presenting people with an image of a robot depicted in different colors representing human skin tones.