Dictators who conduct show trials, and people who force public confessions know what they're doing. We believe our eyes, even if we have been told that we can't believe them.
People think that they make allowance for circumstances, but much of the time they are mistaken. We tend to reserve our exceptional understanding and compassion for ourselves. When we are involved in some unpleasant situation, we blame the circumstances. We snap at someone because we're having an exceptionally hard day, or we're over-tired, or we just misjudged our tone. When other people make mistakes, we don't consider their day. They're just jerks. Their snappishness (or any other failing) is intrinsic to their character.
Two experiments show that there is no admonition explicit enough to force us to consider others' circumstances as readily as we consider our own. Both experiments involved forcing someone to argue a point whether they wanted to or not. In one experiment, done on college campuses in the 1960s, a student in a discussion group was forced to argue for legalized segregation. This was not a popular argument among young people. Blow-back was understandable. However, the student (who was really an assistant, so no actual student would gain the reputation of "racist-on-campus") was explicitly told by the experimenter - in front of the discussion group - to make the argument whether they believed in it or not. Despite literally seeing the order being given, some participants in the discussion group tended to believe that the arguer's views lined up with their argument, and liked the arguer less because of it.
A few years later, scientists repeated the experiment, this time asking people to evaluate an essayists' probable attitudes toward Fidel Castro. They were told ahead of time that the writer was not given a choice as to what argument they would make. Again, after being told that this person's opinions were not in any way related to what they had been forced to write, people still thought that they were likely to support the unpopular Castro. Put in the same situation, of course, people thought it was perfectly clear that their intrinsic values (not liking Fidel Castro) had nothing to do with their circumstances (being asked to write an essay praising Fidel Castro). Even when we're told that what we see a person do has nothing to do with who a person is, we can't quite believe it. Unless that person is us.
Image: Library of Congress
[Via The Attribution of Attitudes.]