People attribute personal characteristics to robots based on the automatons’ appearance, according to new research published August 28 in the Public Library of Science.
Robots that have a mixture of humanlike and mechanical facial features make people particularly uneasy.
“The findings suggest that people take cues from a robot’s face to perceive the personality and mind of the robot,” lead researcher Elizabeth Broadbent of the University of Auckland told PsyPost. “If the robot has a humanlike face on its screen, people perceive the robot has stronger humanlike abilities — to think, recognise emotions, communicate, feel pleasure, pain, and be conscious. People also see a robot with a humanlike face as more sociable and amiable.”
For the study, Broadbent and her colleagues had 30 participants interact with a robot known as the “PeopleBot.” The machine was specifically designed for human-robot interaction research, and came equipped with a speaker to talk, a display to show its 3D virtual face and a blood pressure monitor.
On three occasions, the robot entered a room where the participant was sitting, moved towards the participant, and measured their blood pressure. In each interaction, the robot had a different face. The robot displayed a humanlike model of a face, the same face with a silver metallic coating, or just the words “healthcare robot.”
“When the cues on the robot’s face include a mixture of humanlike and machinelike characteristics, people think the face looks more eerie (creepy),” Broadbent told PsyPost. “While people prefer a robot with a humanlike face, they would prefer a robot to have no face at all than a face that is part-human and part-machine.”
In their study, Broadbent and her colleagues explained that the silver faced robot could be less preferred because it “provides conflicting cues as to whether the face is human or artificial.” The humanlike face is easily identifiable as human, while the text is easily identifiable as non-human. The silver face, in contrast, is not so unambiguous.
The participants told the researchers that the silver faced robot appeared to “lack some emotion” and was “enough humanlike that the silver appearance becomes creepy.”
“The main caveat is that we only had three conditions – a humanlike face, a silver face, and no face. There are lots of other combinations of human and machinelike faces that could be tested in future research,” Broadbent said.