In 1963 he Milgram published his experiments that “showed” testpeople were willingly administering deadly shocks in Harvard Uni. This made him and his research (in)famous. Also it is widely used to explain the behavior of holocaust perpetrators.
However there is huge criticism from e,g. Rutger Bregman writer “humankind” and others as to me and him it is not fathomable that those people really believed they were killing people or at least giving dangerous levels of electricity. After all that would give Harvard a bad name and might get the tester on a real electric chair.
Bregman put up some links to hissources on Twitter :
Here another critical article:
What is your opinion, can this holocaust attitudes be simulated in a lab test.