Read the full article at NPR.

Science fiction writer Isaac Asimov collected a series of his short stories on robots in his now famous anthology I, Robot.

The series "revolutionized science fiction ... and made robots far more interesting than they ever had been," according to the Saturday Evening Post.

I, Robot begins with a lesser-known story: Robbie. Robbie is an experimental robot brought home by George Weston, a robotics engineer, to nanny his 4-year-old daughter Gloria. Quickly, Gloria and Robbie become inseparable. He plays games with Gloria, and she speaks for him and tells stories to the mute quasi-humanoid device. Gloria tells her parents that Robbie is her best friend, she holds his metal hand, and she shares secrets and tears with him.

Meanwhile, Grace Weston, Gloria's mom, goes from uneasy to increasingly concerned about Robbie and her daughter. "It's Gloria and that terrible machine...You listen to me, George. I won't have my daughter entrusted to a machine — and I don't care how clever it is. It has no soul, and no one knows what it may be thinking."

This is fiction — from a time when there were no actual humanoid robots. Now there are. You can find robots in malls, hotels, assembly lines, hospitals and, of course, research labs.

The National Robotics Initiative foresees a future in which "robots are as commonplace as today's automobiles, computers, and cell phones. Robots will be found in homes, offices, hospitals, factories, farms, and mines; and in the air, on land, under water, and in space.

And just as Asimov foresaw, some robots certainly make adults uneasy. Decades of research reveal that while adults prefer robots that are somewhat human-like, they find very human-like robots unnerving. This is known as the Uncanny Valley. Both by hypothesis and according to research, machines become increasingly attractive as they become more human-like until they reach a threshold at which they become too human-like and are considered creepy.

It's this precipitous dip in affinity for very human-like robots that is the Uncanny Valley. Very human-like robots are distinctly creepier than other robots and, in particular, creepier than even unsettling machine-like robots (e.g., clearly machine-like robots whose metal gears and wires are more obvious).

Some scientists think very human-like robots are creepy because we evolved a fear of illness and very human-like robots tend to look like sick humans. Others argue that closely human-like robots give the impression that they can think and feel, but we, as adults, don't believe machines should be able to think or feel. So, robots that look and act like they can violate our expectations are unsettling.

Either of these factors could have caused Grace Weston's fictional uneasiness. Given that Robbie was reasonably human-like, Asimov's story could well have been prophetic. His portrayal of Grace was close to the mark. How about his portrayal of Gloria?

While there were many studies on the Uncanny Valley with adults, there had been no research with children. Do children experience the Uncanny Valley, too?