But the NASA video also taps into something that goes beyond scientific discovery or Saturn. The public mourning of Cassini serves as another example of the complicated relationship between humans and machines, and of the tendency of humans to anthropomorphize robots and care about them.
“That’s how we’re built,” said Doug Gillan, a psychology professor at North Carolina State University who studies human interaction with technology. “We have these social processes, and sometimes they get applied to non-social things.”
The anthropomorphism of machines appears to fall on a rather unsurprising spectrum: The more alive a robot seems, the more likely its behavior will trigger feelings of empathy, attachment, or protectiveness in humans, who are hardwired to respond in such ways to other social beings. Even the slightest perceived hints of life in a machine—like Cassini “fighting to keep its antenna pointed at Earth”—can cause people to see it as something other than just a collection of sensors and circuitry, and then react to it in an emotional way.
Research has shown that people can feel the same kind of empathy for robots as they do for humans. In one study, participants watched videos of a boy and several kinds of robots getting yelled at or being pushed around, and were then asked which they would save in the event of an earthquake. Their picks showed that participants felt more empathy for the boy and the robots that looked and talked like humans than for device-like robots, like a Roomba—but they felt compassion for the Roomba, too. In another study, participants were hooked up to a brain-imaging machine and shown clips of a a woman, a box, and a robotic toy dinosaur receiving affection, and then being physically abused. Participants showed more concern for the human than for the dinosaur, but their brains reacted in a similar way as they watched the dinosaur squirm and let out tiny electronic screams.
Here’s a prime example of a robot that exhibits enough “aliveness” to make humans burst into tears: the fictional Pixar character WALL-E is a rusty trash compactor. But his boxy frame shivers when he’s scared, his shovel hands come together when he’s hopeful, and his giant, binocular eyes tilt downward when he’s sad. R2-D2 looks like a trash can and BB-8 like a soccer ball wearing a Go-Pro, but the Star Wars crew gave them the ability to make expressive squeaks and act in ways that show bravery and loyalty.
The same effect holds for real-life robots. A survey of military personnel that use robots to disarm bombs found that soldiers can feel frustrated, angry, or sad when their robots are destroyed. The soldiers said they’d given the robots names and genders, which may have led them to feel affection for the machines. The DAR-1 is a six-legged, spider-like machine, but it’s designed to track human faces, lock eyes with people, and back away if they get too close, meant to suggest that it feels nervous. The Blabdroid is literally a cardboard box and a set of wheels, but two holes and a thin slit cut into the material create the appearance of eyes and a mouth, making the robot appear friendly.