We’ve all encountered failure. Perhaps, it’s blowing a job interview, failing a final exam, or getting rejected from your dream school. Whether we like it or not, failure is part of life. But eventually, we’re told, overcoming difficult obstacles will make a future success taste so much sweeter. New research, however, may challenge this maxim. In expectation, at least, initial failure can lead people to underestimate how good it would feel to succeed.

Life is full of setbacks. How people respond to these obstacles is of great importance both to their decisions and achievements. Previous research has shown that hedonic expectations are key: “If I should reach that goal, how happy would I feel?” In a recent study, we wanted to understand how such expectations may change in the face of failure. Are people able to predict their own happiness?

The proverb claiming that “the grass is always greener on the other side” suggests that people spend much of their time longing for things they can't have. Marketing teams take advantage of this tendency by reducing the perceived availability of a product to create a sense of scarcity and increase its popularity. According to this logic, the harder it is to attain, the higher the valuation. But is this a good model for how ordinary people process failure?

According to Aesop's fable The Fox and the Grapes, failure often has the direct opposite effect—persuading us to abandon our previous plan. In the fable, the fox is drawn to a bunch of grapes hanging from the vine and tries to leap up and grab them. But, although he jumps with all his strength, he fails to reach the grapes and soon realizes they are hanging too high above the ground. Finally, the fox changes his mind and walks away—concluding that the grapes were probably sour anyway. According to this tale, initial failure can make future success appear less attractive.

So, which is it: greener grass or sour grapes? Inspired by these competing conceptions, our team of researchers turned each narrative into a testable hypothesis and conducted a series of experiments in Norway and the U.S. to determine how people respond to failure.

In the study, about 1,200 participants were randomly assigned to receive either good or poor feedback on the practice trial of a cognitive test. Using a false-feedback procedure, half of the sample was told that they had performed in the bottom 20 percent, while the other half was told that they had performed in the top 20 percent. They were then asked to predict how they would feel if they earned a high score on the actual test, placing them in the top 10 percent. They reported their predictive pleasure on a rating scale from zero to 10, indicating the amount of happiness, gratitude and pride they would feel after earning a top result. In line with modern method standards, the paper also included a preregistered replication study in a large sample, to make sure the main finding was robust.

If the grass is “always greener on the other side,” people receiving poor feedback on the practice trial would predict higher happiness with future success than those who received good feedback from the start. But, if the participants reacted more like Aesop's fox, they would respond less eagerly and try to distance themselves from failure.

Following Aesop's lead, the results showed that initial failure made future success appear less attractive. Specifically, those who received poor feedback on the practice trial predicted that they would feel less happiness, less gratitude and less pride after a top performance, compared to those who received strong feedback from the start. However, later in the experiment, when those same participants received a top score on the actual test, they were just as happy as those who received a strong initial score, and much happier than they had predicted in advance. This suggests that the initial failure made people underestimate how good it would feel to succeed in the future.

Drawing inspiration from Aesop, we termed this phenomenon the “sour-grape effect”: a systematic tendency to downplay the value of unattainable goals and rewards.

The question though, is why failure makes us downplay our future happiness. According to the notion of “adaptive preferences,” put forward by Columbia philosophy professor Jon Elster, people don't always know what they want, and often adjust their desires to what appears within reach. That is, human preferences are sometimes a function of what is possible, rather than what is ideal. This perspective aligns with the cognitive dissonance theory in psychology, which suggests that people seek to maintain a positive and consistent view of themselves. When the outcome doesn’t fit the image they have of themselves, they respond by devaluing the goal—rather than devaluing the self. In other words, when personal failure occurs, one way of protecting our positive sense of self is to deny the emotional relevance of future achievements in order to avoid this “dissonance.”

Our results support the logic that the sour-grape effect is designed for self-protection. Participants who received poor test feedback didn't only predict lower happiness following a future high score; they also claimed that their cognitive performance was irrelevant to their personal identity and future success in life, until they surprisingly received a top result on the actual test. Ultimately, their high happiness ratings after the final result suggest that deep inside, they knew their test performance was relevant all along.

The findings may be surprising for readers with a background in psychology and behavioral economics, as the typical result in previous research indicates that people tend to overestimate their emotional responses to future events—a phenomenon known as “impact bias.” But our study demonstrated a sour-grape effect that goes in the opposite direction, as an exception from the rule. As a defensive response to failure, people may actually underestimate their future happiness after reaching desired goals.

The sour-grape effect suggests that the stories we tell ourselves about what we want in life may be restricted by what we can get. Often, we don't really know what we want, or how much we want it, until we achieve it. Related studies by other research teams have found similar effects in dating scenarios and the political domain, indicating that our current preferences are shaped by the likelihood of reaching our goal. If you believe that it is highly unlikely that you will create a positive change in the world or land your dream job, you may underestimate how good it would feel if it actually did happen. And, as a consequence, this prediction bias might prevent people from fully committing.

But detachment from personal goals can also be a useful strategy, if it helps the person shift their attention from the impossible to better and more achievable goals. As economists put it, “opportunity costs,” or alternative possibilities, should also be taken into account. However, if the sour-grape effect kicks in too early and people become fearful of failure, they could miss out on the chance to try again and realize that what once seemed impossible is now within reach.