Hofling et al. (1996): 22 nurses from 2 separate hospitals were alone in a ward and asked by an unknown doctor over the phone to give an overdose of a drug (Astroten 5mg - really a placebo) that was unauthorised in the specific ward, to a patient; 21/22 nurses started administering, brief calls, only 11 nurses knew dosage limits, no hostility , and all knew it was against hospital rules; strength of authority (doctor) generates obedience, even when possibly endangering a life