Can a robot cry?

A robot can produce tears. Whether that is crying depends on what you mean by the word, and the honest answer separates the two halves.

The mechanical half is real and documented. A robot built at a Japanese university in September 2021 has tear sacs in its eyes and sheds tears, and researchers in Frontiers in Robotics and AI found that adding tears to a robot's face significantly raised how sad people judged it to be, and made them more willing to offer support. Those are findings about the machine's output and about human perception, each attributed to the team that produced it.

The felt half is not established, and the researchers are the ones saying so. The same paper states that as inorganic objects, robots have no emotions or will and do not shed tears spontaneously. The commercial robots people associate with emotion follow the same pattern: SoftBank announced Pepper as a robot that reads emotions, never as one that has them, and the MIT lab that named affective computing describes its work as responding to emotion rather than experiencing it.

So the tears are engineering, and the sadness is in the person watching. DEPLOY scopes the answer to its record and attributes every claim to its source.

What is built vs what it means

Each stance is attributed to who holds it. Notably, the researchers building the tears are also the ones saying the feeling is not there.

How the evidence accumulated

The same findings as a dated timeline, newest first.

1. Jun 1, 2023Adding tears to a robot's face makes people read it as much sadder.Peer-reviewed study

   Akiko Yasuhara and Takuma Takehara tested robot faces with and without tears in Frontiers in Robotics and AI. The tears condition scored significantly higher for intensity of sadness and drew stronger intentions to offer support. The authors are explicit about what this does not show, writing that as inorganic objects, robots have no emotions or will and do not shed tears spontaneously. The study used pictures of robots rather than physical robots, a limitation the authors state.

   Akiko Yasuhara and Takuma Takehara, Frontiers in Robotics and AIFrontiers in Robotics and AI2023-06-01
2. Sep 1, 2021 (as reported)One robot has been built with tear sacs that actually shed tears.Reported demonstration

   The Frontiers study records a robot developed at a university in Japan in September 2021 that has tear sacs in its eyes, moistens them, and sheds tears. Its developer, Associate Professor Sejima, is described as wanting to create an atmosphere in which people find it easier to cry. The tears are a designed output for counselling and stress relief, attributed to the developer, not a response to any state the robot is in.

   Associate Professor Sejima, Japan (recorded by Yasuhara and Takehara)Frontiers in Robotics and AI2023-06-01
3. Jun 5, 2014The best-known emotional robot was sold as reading emotions, never as having them.Commercial product claim

   SoftBank Mobile and Aldebaran Robotics announced Pepper as the world's first personal robot that can read emotions, using emotion recognition that analyzes expressions and voice tones. The company's own wording is precise and worth keeping: Pepper estimates what a person is feeling. Nothing in the announcement claims the robot feels anything itself.

   SoftBank Mobile and Aldebaran RoboticsSoftBank (official press release)2014-06-05

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