A construction worker sneered to a male reporter, "If you were a woman, then. ..." He got up anyway.

Another woman, who sprang up from her seat, twice asked the reporter, who kept her eyes fixed on the ground, if she was O.K.

Dr. Milgram, who died in 1984 at age 51, got the idea for the experiment from a conversation with his mother-in-law, who complained to him one day that no one had offered her a seat on the subway. "It occurred to me: What would have happened had she asked for a seat?" he said in a 1974 interview in the magazine Psychology Today.

He suggested the experiment to one of his graduate student classes, but the students recoiled. Finally, one student, Ira Goodman, volunteered to try it with a partner. But instead of coming back after 20 trials as he had promised, he returned with only 14. When Dr. Milgram asked him what had happened, he said that it was just too difficult.

Dismissing his students' fears, Dr. Milgram set out to try it himself. But when he approached his first seated passenger, he found himself frozen.

"The words seemed lodged in my trachea and would simply not emerge," he said in the interview.

Retreating, he berated himself: 'What kind of craven coward are you?"

A few unsuccessful tries later, he managed to choke out a request.

"Taking the man's seat, I was overwhelmed by the need to behave in a way that would justify my request," he said. "My head sank between my knees, and I could feel my face blanching. I was not role-playing. I actually felt as if I were going to perish."