Dr. Mori’s Uncanny Valley: Fascinating theory on robotics here. Make them lifelike, but not too lifelike.
…the more human-looking a machine becomes, the more people are drawn to it. For example, a robot that has arms and legs and can talk but clearly looks like a machine is typically embraced as a scientific wonder. But at the point when a robot looks and acts almost human but not quite, people are repulsed and the approval rating plummets.
The sudden dip is called the Uncanny Valley because something that comes across as an off-kilter version of humanity is, well, uncanny. It’s profoundly disturbing when something blurs the line between human and non-human.