This combination of time travel and fabulism is a human superpower. It’s hard to fathom any other species doing something so complex, just as it’s difficult to imagine a jellyfish composing a sonnet or a raccoon rewiring a floor lamp.
Yet we deploy this superpower effortlessly. Indeed, it is so deeply imprinted in human beings that the only people who lack the ability are children whose brains haven’t fully developed and adults whose brains have been beset by illness or injury.
For example, in one study, developmental psychologists Robert Guttentag and Jennifer Ferrell read a story to a group of children that went something like this:
Two boys, Bob and David, live near each other and ride their bikes to school each morning. To get to school, the boys take a bike path that circles a pond. Bikers can ride around the right side of the pond or the left side. Both paths are the same distance and are equally smooth. Every day, Bob takes the path around the right side of the pond. Every day, David takes the path around the left side of the pond.
One morning, Bob, as usual, rides around the right side of the pond. But overnight, a tree branch has fallen into the path. Bob collides with the branch, falls off his bike, hurts himself, and is late to school. The left side of the path was fine.
That same morning, David, who always takes the left path, decides instead to ride around the right side of the pond. David also hits the branch, is tossed off his bicycle, gets hurt, and arrives late to school.
The researchers then asked the children, “Who would be more upset about deciding to ride along the path that went around the right side of the pond that day?” Bob, who takes that path every day, or David, who usually rides on the left side but today decided to ride on the right side? Or would they feel the same?
The seven-year-olds “performed very similarly to adults on the measures of the understanding of regret,” Guttentag and Ferrell write. Seventy-six percent of them understood that David would likely feel worse. But the five-year-olds showed little understanding of the concept. About three-fourths of them said the boys would feel the same.[4] It takes a few years for young brains to acquire the strength and muscularity to perform the mental trapeze act—swinging between past and present and between reality and imagination—that regret demands.[5] That’s why most children don’t begin to understand regret until age six.[6] But by age eight, they develop the ability even to anticipate regret.[7] And by adolescence, the thinking skills necessary to experience regret have fully emerged.[8] Regret is a marker of a healthy, maturing mind.
It is so fundamental to our development and so critical to proper functioning that, in adults, its absence can signal a grave problem. An important 2004 study makes that plain. A team of cognitive scientists organized a simple gambling game in which participants had to choose one of two computerized roulette-style wheels to spin. Depending on where the arrow landed on their chosen wheel, they would either win money or lose money. When participants spun a wheel and lost money, they felt bad. No surprise. But when they spun a wheel, lost money, and learned that if they’d chosen the other wheel, they’d have won money, they felt really bad. They experienced regret.
However, one group didn’t feel any worse when they discovered that a different choice would have produced a better outcome: people with lesions on a part of the brain called the orbitofrontal cortex. “[T]hey seem to experience no regret whatsoever,” neuroscientist Nathalie Camille and her colleagues wrote in the journal Science. “These patients fail to grasp this concept.”？[9] In other words, the inability to feel regret—in some sense, the apotheosis of what the “no regrets” philosophy encourages—wasn’t an advantage. It was a sign of brain damage.
The pattern is similar for other diseases of the brain, neuroscientists have found. Several studies present participants with a straightforward test like this:
Maria gets sick after visiting a restaurant she often visits. Ana gets sick after eating at a restaurant she’s never visited before. Who regrets their choice of restaurant more?
Most healthy people immediately know the answer is Ana. But people with Huntington’s disease, an inherited neurodegenerative disorder, don’t see the obviousness. They just guess; they land on the correct response no more often than chance.[10] It’s much the same among people suffering from Parkinson’s disease. They, too, fail to deduce the response you probably intuited instantly.[11] The effect is especially devastating for schizophrenia patients. Their illness scrambles the complex thinking I’ve been describing, creating a reasoning deficit that impairs the ability to comprehend or experience regret.[12] Such deficits are so pronounced in so many psychiatric and neurological diseases that physicians now use this impairment to identify deeper problems.[13] In short, people without regrets aren’t paragons of psychological health. They are often people who are seriously ill.