Analogies and logic.

This is fascinating and quite appalling:

…students of international conflict at Stanford were told of a hypothetical foreign-policy crisis. A small, democratic nation was being threatened by an aggressive, totalitarian neighbor. Each student was asked to play the role of a State Department official and recommend a course of action. The descriptions of the situation were manipulated slightly. Some of the students heard versions with cues intended to make them think of the events that proceded World Was II. The president at the time, they were told, was “from New York, the same state as Franklin Roosevelt”, refugees were fleeing in boxcars, and the briefing was held in Winston Churchill Hall. Other students heard versions that might have reminded them of Vietnam. The president was “from Texas, the same state as Lyndon Johnson”, refugees were escaping in small boats, and the briefing took place in Dean Rusk Hall.

Clearly, there is little reason that the president’s home state, the refugees’ vehicles, or the name of a briefing room should influence a recommendation on foreign policy. Yet subject in the first group were more likely to apply the lesson of World War II–that aggression must be met with force–than were participants in the second group, who veered toward a hands-off policy inspired by Vietnam. Not only were the students swayed by superficial likenesses, they were not even aware that they had been swayed.