Third option alters choice of previous alternatives
A trick that salesmen use to sell expensive cars may help average frogs snag mates.
Female túngara frogs often switch which of two mating calls they prefer upon hearing a third, unattractive mating call, researchers report in the Aug. 28 Science. This action resembles a human behavior known as the “decoy effect.”
“People are really interested in this because it’s such a common thing for people,” says study coauthor Amanda Lea, an evolutionary biologist at the University of Texas at Austin. The decoy effect is a well-known marketing trick, where one wholly unappealing option changes a customer’s preference between two others. For example, a customer might prefer a cheap, compact car over a spacious, expensive sedan. But if a salesman presents a third “decoy” option — a car about as large as the sedan but much more expensive — the customer often changes his mind and picks the sedan.