[eloisant]

I agree - and as a robotics researchers working on humanoid robots told me, if the robot looks too human, users will be reluctant to treat it as a slave and order it around; they'll feel bad about and want to be nice to the robot.

Whereas you never feel bad for making an appliance work 24/7, or to ask your dishwasher to start his work at 11pm.

[Jyaif]

The fix is obvious... make the robot look sad when it's not doing anything, and happy when it is doing something.