The man in the surveillance footage was easy to spot. He was five foot six, about 270 pounds, and he wore nothing over his face.
On January 6, 1995, according to the Pittsburgh Post-Gazette, he and an accomplice went to the Fidelity Savings Bank in Brighton Heights and the Mellon Bank in Swissvale. The cameras caught him with a gun, standing in front of a teller. The accomplice, Clifton Earl Johnson, was arrested on January 12.
Then the robber’s picture ran in the Pittsburgh Crime Stoppers segment of the eleven o’clock news. Informants recognized him. At 12:10 a.m., less than an hour after the broadcast, police arrested McArthur Wheeler, 45.
He could not believe it. “But I wore the juice,” he said.
Wheeler believed that rubbing lemon juice on his face would make it invisible to video cameras. He had not taken this on faith. The Post-Gazette’s reporter, Michael A. Fuoco, spoke to the detectives afterward. Commander Ronald Freeman said Wheeler had performed a variety of tests before the robberies. Sergeant Wally Long added that although the juice burned his face and eyes, so that he had trouble seeing and had to squint, Wheeler “had tested the theory, and it seemed to work.” He had taken a Polaroid of himself, and he was not in the picture.
Long came up with three possible explanations. Maybe the film was bad. Maybe Wheeler hadn’t adjusted the camera properly. Maybe he had pointed it away from his face at the moment he took the shot.
The story landed in the offbeat news section of the 1996 World Almanac, where David Dunning, a social psychologist at Cornell, read it. As Errol Morris recounted in The New York Times, the thought that struck Dunning was that if Wheeler was too stupid to be a bank robber, he might also be too stupid to know it.
Within weeks, by Morris’s account, Dunning and his graduate student Justin Kruger had a program of research. Their 1999 paper tested college students on humor, grammar and logic. Those who scored in the bottom quarter, around the 12th percentile, estimated that they were in the 62nd.
Wheeler’s test had come back clean. That was the problem with it.