The popcorn served in the theater was 7 days old, rubber-band-chewy and about as inviting as four hours of someone else's home movies.
"Actively unpleasant," said David Neal, the psychologist who used the stale bird feed in a study on human behavior that is turning heads and stomachs.
In a project conducted and funded by Duke University, researchers sent 98 people to a theater on the pretense they were participating in a study about what draws consumers to movies. They gave everyone boxes of popcorn. Some boxes had popcorn made an hour earlier; others had the week-old snack.
People who rarely or only occasionally eat popcorn at movies stayed away from the stale sample, eating much more of the fresh snack. The moviegoers who always eat popcorn in the theater, however, were different.
"They ate exactly the same amount regardless if it was fresh or stale," Neal said, adding that a survey showed they realized the week-old popcorn tasted bad. They ate it because they can't sit in a theater without popcorn and their actions are controlled by habit.
"This study highlights the illusion that much of our daily behavior is controlled by what we want," he said. "Much of it is controlled by the environment and what we've done before and our memories of what we've done before."
Lynn McKnerney, standing recently outside a Southern California multiplex to see "Contagion," was skeptical. He's 61, checks out the movies once a week and always eats popcorn.
McKnerney conceded he might swallow the snack if it was a few hours old. But a week?
"People would be crazy," he said.
Kati Munoz wasn't so sure. The assistant manager of a Camarillo, Calif., complex said her theater always makes fresh popcorn with real butter. But if that popcorn were swapped with some born the week before, would moviegoers dump it?
"Probably not," she said, thinking of the regulars who come to the theater every week and load up on the exact same fare. "You go to a movie, and you get a popcorn and a drink."
Candy Bartole, an eating-disorders specialist, thinks of the people who plop themselves on the sofa and rip open a bag of chips or eat chicken soup when they're sick or have ice cream on a bad day. They pick their food based on habit developed over years, she said.
"We do a lot of food pairing," she said. "You can tell someone until the cows come home that if you eat that, you might get diabetes, you might get heart problems, blah, blah, blah. But there's a pairing in the brain about food. ... You're eating the popcorn because it replicates a time in your life that felt good."
Neal, a former University of Southern California professor who now leads a research firm in Florida and Australia, said the study's $3,000 budget included the cost of the popcorn and a small fee paid to the subjects. He said the project goes beyond popcorn and other foods and is aimed at assessing the gap between what people want to do and what they actually do.
"Our behavior starts off being controlled by our goals and desires and preferences," he said. "When we repeat them a lot, the environment takes over."
As a sequel to the Duke study, researchers sent another group to the movies. This time, the popcorn boxes had handles designed so that some people ate with their left hand and some with their right.
The people who ate with their dominant hand ate as much stale popcorn as fresh, as in the first study. But people forced to use their weaker hand had to think about what they were doing. "They only ate the food if it was fresh," Neal said, suggesting the research shows changing routine can alter habits. "It's great to set goals and work on your willpower. In a way, a more powerful thing to do is to structure your environment so it supports healthy choices."
(Contact Tom Kisken of the Ventura County Star in California at http://www.vcstar.com/staff/tom-kisken/)