Research explored some of the reasons people view robots that are too realistic as creepy.

• Human replicas cause creepy perceptions, known as the "uncanny valley." They found that exposure over time decreases the perception of uncanniness.
• While robots can have some human features, there can be too much of a good thing. That can produce feelings of unease, eeriness, and revulsion.

Perhaps that is why animated dolls are more associated with characters in nightmares, regardless of usefulness.

In the age of artificial intelligence, there is a growing number of devices that communicate with us. We give them names like "Siri" and "Alexa" and don't find them threatening - until they are given a face.

Evolving technology can create robots that look like peop...