Lab at Yale university. When pps arrived, greated by 'experimenter' and another 'participant'. = Both confederates. Pps drew slips of paper to decide who played role of teacher or learner. ( Rigged, pps always got teacher) . Leaner strapped to shock machine, teacher in adjoining room sat Infront of shock generator . 30 switches on it , for every 4 switches, shock labels starting at 'slight shock ' to 'XXX'.