The End

Know Your Nuggets: Peak End Rule

Bob Sullivan

Editor's Note: Another one of our Know Your Nuggets!

If you’re involved with event or experience design, you’ve probably heard of the "Peak End Rule.” So it’s about time you knew what it meant.

On a related note, Dan Ariely and I discussed the Peak End Rule in our book about money, but we referred to a study about colonoscopies. (Sorry.) So, my unscientific life advice: Try to remember most of your events and experiences are, at a minimum, "better than a colonoscopy." (Sorry again.)


You visit the in-laws for a Sunday afternoon, and to your pleasant surprise, it's going well. They don't bring up anything awkward, like politics, or ask when you are finally buying a house or getting a new job. But right as you walk out the door, your father-in-law pulls you aside and demands to know who you voted for in the last presidential election. You deftly brush the question aside with a "no politics" joke, but then slink into the driver's seat of the car, and heave a heavy sigh.

It was a lovely afternoon, but now there's bad taste in your mouth. Later that night, as you replay the events of the day, you can't quite shake that bad taste. The last sour exchange seems to trump every other memory you can conjure up of the day.

Why do our minds work like this? Well, we can’t remember everything.

Your mind is simply obeying something called the “Peak-End Rule.” Endings stick in our heads, so a bad ending can really detract from your overall impression of an experience. Being served cold coffee at the end of a meal can make you forget how good your salmon was – and might mean you never dine at the restaurant again.  A long checkout line at a store will make you think twice about going back.  Send a golf ball sailing into the woods on the 18th hole, and you’ll be kicking yourself in the parking lot, even if you played a pretty good round otherwise.

This phenomenon works in reverse, too. A free after-dinner drink can rescue a restaurant that has screwed up a dinner order. A surprise ending can redeem an otherwise pedestrian movie. Score a birdie on the 18th, and you might even suggest your foursome return tomorrow for another round.

Understanding how our memories select these snapshots can be a powerful tool.

Many folks who explain Peak-End Rule rely on the famous Shakespeare line, "All's well that ends well," but that only tells half the story of this phenomenon. It was originally called the “Peak & End” rule. When Daniel Kahneman described it back in 1993, he was actually talking about the two most powerful moments in our memories of an experience – the ending, as we've discussed, and the most intense, or peak, moment.

Why do our minds work like this? Well, we can’t remember everything. We don’t have video libraries in our brains capable of re-playing every moment. Instead, we selectively remember snapshots. These tend to be the peak event, and the ending event.  Understanding how our memories select these snapshots can be a powerful tool.

Kahneman’s famous Peak-End experiment involved asking subjects to dip their hand in ice cold water and endure the mild pain for 60 seconds. Then they did the same thing, only an additional 30 seconds of not-quite-so-cold submersion was added. The test offered a “better end.” When asked to repeat the experiment, a wide majority preferred the second experience, even though the total time in pain was actually increased.  People were tricked into picking more pain just because the discomfort eased towards the end.

Here's a more painless Peak End example. Study participants were given free DVDs – some so-so movies, and some blockbusters. The order in which they received the gifts mattered.  Those who received the more popular movies at the end reported being more satisfied than those who got the duds at the end.

Both those tests say a lot about happy endings, but peak intensity has its own deep impact. A flight that lands smoothly doesn’t diminish the lingering impact of that surprise mid-flight turbulence: You’ll still say it was a rough trip.

There is an unlimited amount of business implications for Peak-End rule: For starters, as mom said, always make sure you say a polite good-bye.  Smart retailers put someone at the door to offer a deep-look-you-in-the-eye, chipper “thanks for coming” and “Did you get find everything you need?”  Contrast that with exiting a big box store and being compelled to show a receipt by “inventory control agents.”

There are plenty of applications for the Peak-End Rule in the workplace, too.

Perhaps even more important, Peak-End Rule means you might be able to right a wrong. So keep trying, even when an interaction seems to go sour.  In one study involving long waiting lines, consumers who experienced surprisingly quick movement at the end of a long wait could be “turned” into reporting their wait as satisfying.

There are plenty of applications for the Peak-End Rule in the workplace, too. On basketball courts across the world, players always want to leave on a “made” shot. Ending on a high note really does work. When having difficult meetings or one-on-one discussions, save some good news for the end. When groups are struggling to complete large assignments, find smaller “low-hanging fruit” tasks that can be finished at the end of the day or the end of the week.

Of course, happy endings can’t erase everything, so be judicious when trying this out. Some studies suggest that the longer the unpleasant experience, the weaker the Peak-End impact. A cookie granted at the end of hotel stay that was marred by days of noisy construction will not lead to a positive TripAdvisor review. If you really disagree with something I wrote in the middle of this story, no clever turn of phrase at the end here could redeem this piece for you. (Editor’s note: Ain’t that the truth?) On the other hand, just in case you’re on the fence, you can be sure I won’t bring up politics at the end here. Instead, a word of advice to restaurants everywhere: Stop grabbing my plate before I’m finished eating!  That last bite really does matter.

Editor’s extra note: Here’s a picture of some puppies.

Bob Sullivan


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