Psychologists have uncovered a new uncanny phenomenon called the “clone devaluation effect”

New research published in PLOS One provides evidence that duplicated human faces tend to elicit negative emotions in viewers. The findings serve as a warning that future robotic or cloning technology could provoke unpleasant psychological reactions.

“The rapid development of humanoid technology is very exciting for people. However, when I imagined the future mass production of androids, I thought that we might be surrounded by human-like entities with the same face (like Agent Smith in the Matrix),” said study author Fumiya Yonemitsu of Kyushu University, who is also a research fellow at the Japan Society for the Promotion of Science.

“I love science fiction stories that frequently include such situations, but I was horrified to think that this is what the imagined future world would actually look like. I was also curious if this is an emotional response that humans have in general.”

Psychologists have uncovered a new uncanny phenomenon called the “clone devaluation effect”

“Our previous cognitive psychological research has repeatedly shown that unfamiliar and unknown objects evoke an uncanny feeling (e.g., Yamada et al., 2013), and the scene with all the same faces is exactly the kind of ‘unfamiliar and unknown situation’ that violates our expectations of what a real scene should be like,” Yonemitsu explained. “I believe that such a situation also evokes a sense of uncanny, and this is the reason why I wanted to try to conduct this study.”

In six experiments, which included 2,135 Japanese adults, the researchers consistently found evidence that clone human faces induced a sense of eeriness and improbability. “The main finding in this research is that we have an eerie impression of people that have faces with the exact same appearance, which is named the clone devaluation effect,” Yonemitsu told PsyPost.

“This suggests an ironic future. Even if technology is highly advanced enough to overcome the uncanny valley, if we implement a large number of mass-produced humanoid robots all over the world, as we do with today’s consumer electronics, there will be new uncanny phenomena.”

The researchers found that as the number of the clone faces in a scene increased, so did subjective ratings of eeriness. Seeing four clone faces was viewed as stranger than viewing two clone faces. But the results appear to be limited to humanoid faces. Clone dog faces were not associated with heighted eeriness ratings, possibly because humans have “difficulties in distinguishing the individual faces of other species.” In addition, clone human faces drawn in anime and cartoons images were viewed as less eerie and improbable than clone faces in photographic images.

“In our experiment, both the clone and non-clone faces used as stimulus images were edited by swapping the facial parts. Therefore, the amount of collage was the same in both conditions, and it is unlikely that the failure of image editing caused the clone devaluation effect,” Yonemitsu explained.

Yonemitsu and his colleagues also examined the faces of famous twins. They found that the subjective eeriness of twins’ faces tended to be lower than that of clone non-twins’ faces. This could indicate that the duplication of identity, rather than just the duplication of facial features, is what induces eeriness.

“This research does not argue that multiplets (e.g., twins) are eerie. As shown in the paper, the research provides findings that clone faces are less eerie when they are multiplets. I would like to strongly emphasize this point, as it is easily misleading,” Yonemitsu explained.

But the study — like all research — includes some limitations.

Psychologists have uncovered a new uncanny phenomenon called the “clone devaluation effect”

“The clone faces presented in this study were images only. We know that some concerns exist in this regard in terms of construct validity and practicality. The ideal measurement would be to actually produce a number of cloned humans or androids with the same face beyond the uncanny valley and ask people for their impressions. But that is realistically impossible,” Yonemitsu said.

“So should we just leave this problem alone? We did not think so. Therefore, future research will have to consider its limitations and go beyond them. For example, it will be necessary to have the participants look at the faces of the clones in a more realistic environment, for example, by using virtual reality or by using actual human beings who have been given special makeup to make them look the same.”

The findings highlight the need to think critically about introducing new technology because of the potential for unpleasant psychological reactions, the researchers said.

“Although our research suggests that the great development of technology may bring us rather unpleasant situations in some aspects, we believe that research from a psychological point of view, such as this one, which anticipates future situations, plays an important role in order for people to smoothly accept the results of technological innovation and enjoy its benefits,” Yonemitsu told PsyPost.

“If we imagine the future, there could be a large number of psychological phenomena that we have not yet explored, and we can find many hints of them in science fiction works. I would like to end by saying that psychologists can greatly expand the scope of their research beyond the current realm.”

The study, “The clone devaluation effect: A new uncanny phenomenon concerning facial identity“, was authored by Fumiya Yonemitsu, Kyoshiro Sasaki, Akihiko Gobara, and Yuki Yamada.