Why Do We Love R2-D2 and Not C-3PO?

With its stubby cylindrical body and playful whistles and beeps, the lovable Star Wars’ robot R2-D2 is just the right mix of man and machine

Dan Winters / © & ™ Lucasfilm Ltd.

Many Star Wars characters loom large in the imagination—the sepulchral Darth Vader, the swaggering Han Solo, the take-charge Princess Leia. But one character implausibly worked its way into people’s hearts: R2-D2.

With its stubby little body, blooping voice and wide round eye, R2-D2 was a curiously endearing machine. Fans went crazy for the droid, knitting winter hats in its shape and building computer cases that looked like its body. Even Star Wars actors went a bit googly-eyed when they were on the set alongside the droid.

“There is something about R2-D2,” as the robot’s original designer, Tony Dyson, has said, “that people just want to cuddle.”

In 1983, when Return of the Jedi was released, Smithsonian curator Carlene Stephens wanted to preserve an artifact from this pop-cultural moment. The Smithsonian contacted Lucasfilm executives, who sent over one of their R2-D2 models, along with its companion, C-3P0. The R2-D2 pictured here is now part of the Smithsonian’s permanent collection.

But what precisely is the source of R2-D2’s allure? There are plenty of movie robots. Few stir emotions as richly as this one—particularly given that it looks, as Stephens jokes, “like an industrial vacuum cleaner.”

Yet that might be the secret to its appeal. To understand R2-D2, you have to wrap your mind around a
theory called “the uncanny valley.”

The concept was first posed in 1970 by the Japanese roboticist Masahiro Mori. He’d noticed that as robots grow more realistic, people’s attitudes toward them change. When a robot is toylike and capable of only simple, humanlike gestures, we find it cute. If it starts looking and acting a bit more human, we find it even more endearing. But if it gets too human—as with, say, a rubbery prosthetic hand—we suddenly shift allegiance. We find it creepy. Our emotional response plunges into what Mori called the uncanny valley.

Why would overly realistic robots so unsettle us? When they become nearly human, we start focusing on the things that are missing. We notice that the arms don’t quite move as smoothly as a real human’s, or the skin tone isn’t quite right. It stops looking like a person and starts looking like a zombie. Angela Tinwell, a professor specializing in video game design at the University of Bolton in Britain, suspects we unconsciously detect sociopathy or disease.

Mori saw a way out of this conundrum. The most engaging robot would be one that suggested human behavior, but didn’t try to perfectly emulate it. Our imaginations would do the rest, endowing it with a personality that we could relate to.

In essence, Mori perfectly predicted the appeal of R2-D2.

“R2-D2 was really charming,” Tinwell says. “Any humanlike traits you could perceive in him made us like him more.” When the robot whistled and beeped rejoinders to its friend, the neurotic droid C-3P0, audiences thought “Oh, I can relate! He has a sense of humor!”

Indeed, R2-D2 was famously brave, plunging into bruising laser-gun battles to help its comrades. (Like an interstellar Forrest Gump, the robot always managed to turn up at the absolute center of the action.) R2-D2 was also useful. Its body contained tools ranging from computer interfaces to blowtorches. Director George Lucas was so enamored of the robot that he insisted it should save the day once every movie—as in The Empire Strikes Back, when R2-D2 fixes the Millennium Falcon’s hyperspace engine moments before being caught in the tractor beam of an Imperial Star Destroyer.

Even R2-D2’s “voice” avoided the uncanny valley—it wasn’t a voice at all but bleeps and bloops created by sound designer Ben Burtt, who used an audio synthesizer.

This was a big cultural shift. Designers had spent centuries making androids in the image of humans. For example, the Smithsonian’s collections include a clockwork automaton friar from about 1560. “The eyes move side to side, the artificial jaw moves up and down, the arm moves a rosary to the lips of the figure as though kissing this thing,” says Stephens. “But it is very weird. It attempts to look like a human and doesn’t quite make it.”

R2-D2 changed the mold. Roboticists now understand it’s far more successful to make their contraptions look industrial—with just a touch of humanity. The room-cleaning Roomba looks like a big flat hockey puck, but its movements and beeps seem so “smart” that people who own them give them names. In Hollywood, Wall-E succeeded with a gang of lovable robots that looked like toasters. The worldwide affection for R2-D2 helped show designers the way out of the uncanny valley. This is the droid we had been looking for.

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