Why do android robots sometimes give us the heebie jeebies?

Nobody calls C3PO creepy, eerie, or spooky. But humanoid doppleganger social robots like Nadine are being found unsettling by many, both because of their appearance and also due to ethical issues connected to the ways they may be used. Nadine is a social robot made in the likeness of creator Professor Nadia Thalmann from Nanyang Technological University (NTU Singapore). Nadine is programmed with intelligent "assistant" software similar to Siri (the Apple computer program that works as an intelligent personal assistant) and Siri's Microsoft counterpart Cortana. Nadine, however, also expresses a version of moods and emotions with the ability to remember the people she has met before as well as conversations.