Why Mistakes Are Often Repeated

Several recent studies show how the brain fails to learn from past experience, dooming us to relive our errors.

Mario Anzuoni / Reuters

If there’s anything that stings more than wasting good money on a subpar outing, it’s doing so repeatedly—but still, the depths of TripAdvisor teem with accounts of mistakes that were made not once, but twice.

“Came back for lunch even though I didn’t enjoy my last meal here,” writes one unfortunate diner whose salad at a restaurant in Bunbury, Australia, came drenched in dressing.

Another guy found the Sistine Chapel a little meh. “Sure I could glance at the magnificence of the final judgment, but not for long as inevitably someone bumped me,” he harrumphed about his initial visit, adding that he later returned (why?) when friends were in town.

“Never again!” concluded a food-poisoned reviewer about a restaurant in Newport, Oregon—who clearly would’ve done well to follow her own advice the first time around.

To err is human, surely. But why do so many people make the same errors over and over again? Several recent studies reveal how our brains don’t learn from our past mistakes to the extent we might hope. In fact, thinking about past flubs might only doom us to repeat them.

For one thing, we seem to learn little from our past choices, good or bad. In a series of experiments published in the Journal of Consumer Psychology, Kelly Haws, an associate professor of marketing at Vanderbilt University, asked some participants to recall times that they were successfully able to control their temptation to impulse-buy, and others to recall times they weren’t. Within each group, some subjects were asked to remember two instances and others 10, the idea being that it’s more difficult to remember many events than just a couple. She then asked them how much credit-card debt they’d be willing to incur in order to buy a coveted item.

Oddly, among the participants asked to recall past successes, those who remembered more examples were willing to take on about 21 percent more credit-card debt than those who remembered fewer. Perhaps, Haws speculated, they struggled to remember all 10 and then questioned their self-control. “They think, ‘If I were that successful, it would be easier for me to recall these successes,’” she said.

But the participants who remembered times when they had failed to rein in their expenditures—regardless of how many instances they recalled—racked up just as much debt as those who reflected on 10 successes. The fact that they had wasted money in the past had little effect on their willingness to do it again.

Seeing yourself as a failure, Haws explained, can get you down. “And when we’re feeling down, we tend to splurge,” she said.

The common proverb intended to counteract mistake making—“just slow down!”—might not help much, either. After making a mistake, our brains typically do slow down the decision-making process the next time a similar issue comes up, through a phenomenon known as “post-error slowing.” However, that doesn’t always make the next decision more accurate.

That’s because our brains rely on poorer-quality evidence from the surrounding environment the second time, according to Roozbeh Kiani, an assistant professor at New York University’s Center for Neural Science. Braden Purcell, a post-doctoral fellow in Kiani’s lab, recently observed this pattern in a study for which he monitored brain activity in humans and monkeys as they made mistakes during a computer game.

The study participants watched a collection of moving dots on a screen, and then used their eyes to indicate the direction in which they thought the majority of the dots were traveling. Both humans and monkeys took longer to make their next decisions after a wrong answer, with the effect more pronounced for difficult choices than for easier ones. The slowness didn’t make them likelier to be right, though, suggesting that the subjects were consistently using weaker information to decide.

The reason for the reliance on worse information might be that “the brain gets involved in a quest to understand why the error took place,” Kiani said. It tries to figure out, why did this error happen? Did something about the world change? Is there something wrong with me? “The negative feedback triggers a cascade of computations,” Kiani said, which distract from the decision at hand.

In the study, this didn’t happen when researchers had subjects wait a
short while before attempting the task again. That pause gave subjects’ brains a chance to recover from the negative feedback. In other words, if you’re playing basketball, and you keep missing baskets, it might be best to try again another day.

In 2008, researchers at McMaster University in Ontario found a similar problem took place with “tip of the tongue” phenomenon. “This can be incredibly frustrating — you know you know the word, but you just can’t quite get it,” the researcher Karin Humphreys told LiveScience at the time. “And once you have it, it is such a relief that you can’t imagine ever forgetting it again. But then you do.”

The reason? The time you spend sifting for that word reinforces a “mistake pathway” in the brain, essentially digging yourself further into the wrong groove. The next time you’re hunting for the elusive word, your brain will reflexively draw a blank instead.

There’s also evidence that our brains are wired to pay attention to things that were rewarding once, even if they aren’t anymore. For a small study recently published in the journal Current Biology, Johns Hopkins University neuroscientists had 20 people find red and green objects among shapes on a computer screen. They were paid $1.50 for each red object and 25 cents for each green one. The next day, the researchers had them do the same thing, but this time they were told they would not be rewarded for finding either color. Still, participants zeroed in on the red objects over the green ones.

The results showed “we're not aware of what we’re paying attention to and why,” said Susan Courtney, a cognitive neuroscientist at Johns Hopkins University and a co-author of the study. “There’s nothing inherently rewarding about these colors, it’s just their experience the day before for an hour.”

To Courtney, the study helped explain why it’s so hard to kick bad habits or stick to diets. “When my gaze drifts toward the donuts in the mailroom, that triggers a thought process of what it would be like to taste that donut. That makes it harder to resist,” she said.

People were especially distracted by the red shapes when they had high levels of the pleasure chemical dopamine surging through their brains. The best strategy, in that case, is to remind yourself about the long-term consequences of eating the donut, the negativity of which might tamp down the dopamine.

Haws agreed that, according to her findings, if you want to avoid repeating history, it’s best not to try to learn from it. Instead, think about the future and what you can achieve if you avoid pitfalls—like a certain dining establishment in Newport, Oregon.