The Decoy Effect (Department of Human Behavior)

Another interesting article from Shankar Vedantam, this time about biases in decision making when faced with more than two choices. Here are a few excerpts:

"Front-runners are usually focused on racing each other. They often do not realize that when people cannot decide between two leading candidates -- and it doesn't matter whether we are talking about politicians or consumer appliances -- our decision can be subtly swayed by whoever is in third place."

"Joel Huber, a Duke University marketing professor, showed how the decoy effect works with restaurants. Huber asked people whether they would prefer to eat at a five-star restaurant that was far away or at a three-star restaurant nearby. As with many choices in life, each restaurant had different advantages. If the better restaurant was also nearby, there would be no dilemma. But the question forced people to compare apples and oranges -- trade off quality against convenience -- which ensured no automatic answer."

"The human brain, however, always seeks simple answers. Enter the third candidate. Huber told some people there was also a choice of a four-star restaurant that was farther away than the five-star option. People now gravitated toward the five-star choice, since it was better and closer than the third candidate. (The three-star restaurant was closer, but not as good as the new candidate.)"

"Many people lavished hate on Ralph Nader for presumably taking votes away from the Democratic front-runner in the 2000 presidential election," said Scott Highhouse, who has studied the decoy effect at Bowling Green State University. "Research on the decoy effect suggests that Nader's presence, rather than taking votes away, probably increased the share of votes for the candidate he most resembled."