Some of psychology's most famous experiments are those that expose the ... apparent cowardice or depravity pooling in almost every heart. The findings force a question. Would I really do that? Consider the psychologist Stanley Milgram's obedience studies of the early 1960s. In a series of about 20 experiments, hundreds of decent, well-intentioned people agreed to deliver what appeared to be increasingly painful electric shocks to another person, as part of what they thought was a learning experiment. The learner" was in fact an actor, usually seated out of sight in an adjacent room, pretending to be zapped. Now, decades after the original work ... two new papers illustrate the continuing power of the shock experiments. [One] verifies a crucial turning point in Milgram's experiments, the voltage level at which participants were most likely to disobey the experimenter and quit delivering shocks. At 75 volts, the "learner" in the next room began grunting in apparent pain. At 150 volts he cried out: "Stop, let me out! I don't want to do this anymore." At that point about a third of the participants refused to continue, found Dominic Packer, author of the new paper. "The previous expressions of pain were insufficient," Dr. Packer said. But at 150 volts, he continued, those who disobeyed decided that the learner's right to stop trumped the experimenter's right to continue. Before the end of the experiments, at 450 volts, an additional 10 to 15 percent had dropped out. The other paper ... replicates part of the Milgram studies ... to see whether people today would still obey. The answer was yes. Once again, more than half the participants agreed to proceed with the experiment past the 150-volt mark.