In another variation, the teacher actually had to physically press the (fake) pupil's hands onto the device that gave electric shocks. IIRC, this squicked out a few more people, but quite a large portion still went through with it.
Proximity to the teacher was the biggest influencer rather than proximity to the student. When the teacher was further away (in some simply on a phone) the subject would more frequently refuse, more so than when they were in close proximity to the student.
Proximity to the student shouldn't be ruled out, after all it would get a few more people behaving like they really should, however its these screening people's proximity to their bosses that is the biggest influence on whether they treat a person with humanity or not.
