Focus On A Chase Cuts Mental Notice Of Side Events

Boston police officer Kenny Conley, convicted of perjury for claiming he did not see a beating as he ran past after another suspect (who was the correct suspect btw), likely was telling the honest truth. Researchers at University of Illinois at Urbana-Champaign and Union College staged similar incidents to test student ability to notice what was going on and two thirds of the students missed the fight.

To test whether someone could actually run past a fight without seeing it, Chabris and his students set up an experiment in which subjects had to "chase" a researcher for three minutes on a college campus. The subjects, who were tested individually, had to follow the runner at a distance of about 30 feet and count the number of times he touched his head. On the way, the subjects passed a staged fight about 8 meters (26 feet) off the pathway they were using. "We tried to set up conditions that were as similar as we could to the situation Conley faced while still maintaining experimental control," Chabris said. "Two students were beating up a third, and they were kicking and punching and yelling and coughing." A first study was conducted at night to simulate the original incident. The researchers then repeated the experiment during daylight.

I think we fool ourselves about how well our minds and process and remember what is going on around us. Therefore we have too much trust in eyewitness accounts and in our own memories. There are implications here for our criminal justice system, civil courts, and other institutions.

Students chasing someone were less likely to notice a beating at night. But even during the day the percentage who missed it was substantial.

"At night, which was when officer Conley had his experience, only about a third of people noticed the fight," Simons said. "When we did it during the day, over 40 percent still missed it." "One of the hallmarks of inattentional blindness is that increasing the demands on a person's attention decreases the likelihood that he or she will notice something unexpected," Chabris said.

Giving the chasing students 2 things to do further reduced the odds of noticing a fight.

To verify that inattentional blindness was involved, some study subjects were asked to keep separate counts for the number of times the runner's right hand and left hand touched his head. "Keeping two counts made them much less likely to notice the fight than keeping no counts," he said.

It would be interesting to see the same sort of experiment done on bank hold-ups, convenience store hold-ups, car accidents, and other things that could be staged with cameras to record what really happened. How much do people get right?