This is an older nautilus article, but man they write well...
"Well, that's vaguely terrifying," said the guy who lives on the west side of LA.
Ooo, ooo, ooo, I got this one. For a project in multivariate calculus back in college I modeled sine chords in 3D space (using paper mache - we were old school back then). The more minor a key, the longer the cycle of repetition. Simple waveforms are harmonic and major. Complex, beating waveforms are disharmonic and minor. We associate pure tones with happiness. Don't ask me why.
Sherry Turkle, based on 30+ years of research, has argued that the way machines model emotion will always be so different, and the mechanisms by which machines use emotion will always be so alien, that it's purest fallacy to pretend that machines will ever be "alive" the way we are. She also points out that because of the way humans are hard-wired to respond to each other, we won't give a shit. If she presents about 20% of the cues of human interaction from a robot, humans will go the other 80% of the way with nary a regret, even though they know they're interacting with a machine. We're so used to providing context that when ELIZA sits across from us providing semantic rules, we imagine the human on the other end.
Asimo with fur right there. Everybody knows it. But Paro is revolutionizing healthcare in Japan.