College students were asked to read a story about a rather daft person, and then take a test. They did worse on that test than a control group that read a story about a non-idiot:

Sixty-three Austrian students read "Slow on the Uptake," about Meier, who wakes, is confused by an adage on his calendar, gets drunk, attends a soccer match and misses the outcome because he brawls. The students either summarized the story or underlined passages where Meier differed from them. A control group of 18 read a story with an innocuous protagonist.

Afterward, on a difficult test covering geography, science and the arts, the students who had read about Meier but not underlined how he differed from them scored from 30% to 32%, compared to about 37% for the control group and for students who distanced themselves from the character.

Hollywood mentioned this tendency a few years ago.

Link -via Althouse | Image: Despair