Suppose that, seeking a nice evening out, you pay $175 for a ticket to a Broadway musical. Seated in the balcony, you quickly realize that the acting is bad. Do you head out the door at the intermission, or stay for the duration?

Studies of human decision-making suggest that most people will stay put, even though money spent in the past logically should have no bearing on the choice.

This «sunk cost fallacy,» as economists call it, is one of many ways that humans allow emotions to affect their choices, sometimes to their own detriment. But the tendency to factor past investments into decision-making is apparently not limited to Homo sapiens.

In a study published last month in the journal Science, investigators at the University of Minnesota reported that mice and rats were just as likely as humans to be influenced by sunk costs.

The more time they invested in waiting for a reward, the less likely they were to quit the pursuit before the delay ended.

«Whatever is going on in the humans is also going on in the nonhuman animals,» said A. David Redish, a professor of neuroscience at the University of Minnesota and an author of the study.

More important than the similarity among species was the study’s finding that sunk cost effects appeared only after the subjects had decided to pursue a reward, Dr. Redish noted, not while they were still deliberating whether to do so.

In effect, the animals seemed to consider the deliberation time not to be part of their investment — an indication, Dr. Redish said, that different brain processes might be at work in different aspects of decision-making. The idea runs counter to the notion that «time is time, and you’re wasting it either way,» he said.

Shelly Flagel, an associate professor of psychiatry at the University of Michigan who was not involved in the study, said the research had «far-reaching implications.»

For example, she said, the behavior is reminiscent of the conduct «exhibited by people with addictions.»

In the study, led by a doctoral student, Brian M. Sweis, three research laboratories at the University of Minnesota collaborated to conduct tests on mice, rats and humans. The rodents were trained to forage for flavored pellets in a square maze with a «restaurant» in each corner.

The humans were taught to «forage» on a computer for videos of kittens, a dance competition, landscapes or bicycle accidents. Both rodents and humans were given a time limit for the foraging tasks.

In the rodents’ task, the animal first entered an «offer zone» outside a restaurant and heard a pitched tone that informed it how long the wait would be for the pellet reward — a delay that varied randomly from 1 to 30 seconds.

The animal could skip the offer, in which case it was withdrawn, or it could enter the «wait zone» of the restaurant, setting off a countdown signaled by a descending tone. At any time during the countdown, the rodent could choose to leave the restaurant.

In the human version of the experiment, subjects were offered a video and presented with buttons saying «stay» or «skip.» A download bar informed them how long they would have to wait to view the video. Clicking the «stay» button started a countdown, and the screen showed the progression of the download.

The study found that the more time the rodents spent in the «wait zone,» the more likely they were to stick out the delay to the end, even though the longer they waited, the more it cut into their time to seek food.

Similarly, the longer the humans spent waiting for a video to download, the more likely they were to stay the course.

Surprisingly, the amount of time that the subjects spent deliberating whether to accept the «offer» did not affect whether they quit or stayed.

«Obviously, the best thing is as quick as possible to get into the wait zone,» Dr. Redish said. «But nobody does that. Somehow, all three species know that if you get into the wait zone, you’re going to pay this sunk cost, and they actually spend extra time deliberating in the offer zone so that they don’t end up getting stuck.»

The ‘sunk cost fallacy’ claims more victims.

© 2018 The New York Times