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The Pigeon Work Ethic

by Sarah Ligon

Ever wonder why a misty glass of lemonade, clinking with ice cubes, tastes better if you have to jog a mile under the hot July sun to get it? Well, so has UK psychology professor Thomas Zentall—and he may have the answer.

Zentall found that pigeons were happier with a reward earned by tiring work than with the same reward offered after little effort.

Three years ago, he began to explore the relationship between work and reward value using White Carneaux pigeons. Each was placed in a holding box alone, faced with a single white plastic button.

During half of the trials, the button turned red after one peck and dispensed a pigeon-size serving of grain. But during the remaining trials, the pigeons pecked over and over with no response. The button had to be hit 20 times before it changed color, this time to green, and the same grain serving was offered up.

After 100 trials a day for 20 days, the pigeons were veterans at both red and green button-pecking. So Zentall gave them a third test: this time, the bird could choose either red or green. He reasoned that the pigeon would most likely opt for red, the color that had led to the easy treat. But the pigeons picked green—the 20-peck button—twice as often as red.

Are the pigeons satisfied by hard work? Or just too stupid to identify the easier job?

Neither, Zentall suggests.

"One interpretation of this is that the pigeons are somehow evaluating the colors, thinking, 'If I worked this hard for it, the green button must be worth more.'" The pigeon might be trying to justify the hard work by assigning the 20-peck grain extra value—a contradiction of beliefs and behavior known to social psychologists as "cognitive dissonance."

Zentall gives an example of a student who earns an "A" in both basketball and organic chemistry, but is happier with the chemistry grade because she worked harder for it. "It's exactly the same 'A,'" Zentall points out. "But according to cognitive dissonance theory, she has to justify her hard work by assigning the chemistry 'A' a higher value."

But Zentall believes there might be an even simpler explanation. "When you've worked with pigeons," he says, "you realize that they don't seem quite as smart as that."

Instead, he suggests that the green button choice stems from the amount of change in the animal's mental state from before and after it gets fed. During the red, one-peck button trial, the pigeon's mood barely alters. "He goes from just OK to happy," Zentall says. "But the 20-peck trial causes more discomfort. Its reward makes the pigeon change from frustrated to happy." So the pigeon chooses green because it had the greatest effect on the pigeon's mood. "This is a simpler explanation," he says. "It's more biological, put in terms of the relative state of the organism."

This concept applies to the hypothetical chemistry student, as well. "When you take organic chemistry, and you finally get through it, the relief is a wonderful thing. But playing basketball was already pretty fun to start with, so the 'A' doesn't make you feel much better."

Zentall suggests that the pigeon's shift in "relative state" may explain the human concept of work ethic. "The major reason for this research," he explains, "is to demonstrate a kind of continuity across species—certain fundamental things that are generally true." Zentall believes that his funding from the National Institute of Mental Health may have been awarded because of such possible connections between his research and our own behavior.

Why use pigeons to unravel mysteries of the human psyche? Zentall, who has worked with pigeons for 30 years, describes his animals as "the farmhorses of the bird family." They're easy-going, reliable, and live for up to 20 years as opposed to a lab rat's two.

"I really enjoy this kind of research," says Zentall. "It's like solving a puzzle—you have to figure out how to communicate with an animal about what you want him to do and then get him to answer." He grins. "That's the reward I get from doing the research."