Of all the cyborgs, androids, and automatons in pop culture media, why does one stand out as such a fan favorite? I'm talking, of course, about R2-D2. When seen scooting around Disneyland, conventions, and Maker Faires, the beloved droid attracts a flock of admirers, young and old. People can't help but love R2. But why don't other sci-fi robots get the same kind of adoration? Peter Novak of Alphabeatic and writer Clive Thompson have a theory: the appeal of R2 lies in his distance from the so-called uncanny valley. As Thompson wrote for The Smithsonian Magazine, "The most engaging robot would be one that suggested human behavior, but didn’t try to perfectly emulate it." R2's beeping and booping has a ton of personality, but it's our imagination that grants him believability as a character. The design of industrial droids like R2 was a paradigm shift in robot design, something that both filmmakers and real toy makers are still trying to perfect. But there's one recent robot that meets the psychological criteria for endearment, which we've seen firsthand elicit unbridled glee from fans: Wall-E!