 The peak end rule is a psychological phenomenon that occurs when people judge an experience largely on how they felt at its peak and its end. There are two reasons for this. More emotionally intense events lead to better memories than less intense events. So if you experience a drama, the peak is what's most moving, and to the mind that's the most vivid mental snapshot. We have a better memory of the end of a sequence, a phenomenon known as recency bias. If you get to eat three different desserts in a row, the second dessert forms a new memory that makes it harder for you to recall the first. And when you've finished all three, your brain remembers the last one most clearly. However, the rule does not always work. As we go into an experience, our expectations play a lead role. If they are initially not met, our prediction error can affect our perception of what's about to come next, including the peak. But for now, let's assume that everything goes according to plan. Say you go to eat out at a cheap diner, and your expectations are low, then the memory of your evening will be formed by the peak and the end. The dry salad, the bad music, and the dirty bathroom are long forgotten. Later, you might rate the experience as exceptional, but what if your expectations are not met? If you go out to eat at an expensive restaurant, you can have high expectations. If the initial experience doesn't meet them, your mind decides that the place isn't that good after all, and you'll see everything through an overly critical lens. The peak is discounted, the end outrageous, and then the overall experience is rated poorly. So if expectations are low, the rule works. If they are high, it's important that they are met right at the start. Evidence for the rule was established through an experiment in which people were subjected to an unpleasant experience in two different ways. The first trial had people submerge a hand in cold water for 60 seconds. In a second trial, people put their hand in the same cold water for the same amount of time but then kept it there for another 30 seconds, during which the temperature was raised by about one degree Celsius. The subjects were then offered the option of which of the two trials to repeat. And as it turns out, they were more willing to repeat the second trial, despite the prolonged exposure to the cold water. Kahneman, Fredrickson, Schreiber and Radelmeier, who conducted the study in 1993, concluded that people chose the long trial simply because they liked the memory of it better than the alternative. If you happen to run a restaurant and manage to meet your customer's expectations, you can create a wonderful peak, finish with a fantastic end, and deliver an experience that's not only excellent but will also be remembered as such. Now what do you think about the rule, and did you ever make your own peak end experience? Please share your thoughts and what you remember from this video in the comments below. If you like how we explain complicated ideas in simple cartoon animation, you can support us. Visit patreon.com slash sprouts. Just visit us, learn how it works, and what's in it for you. We hope to see you there. And if you are a parent or educator, check out our website, sproutschools.com. There you can find this and other video lessons, additional resources, and classroom activities. If you found this helpful, check out our other videos and subscribe. If you want to support our work, join us on patreon.com slash sprouts. For more information and additional content, visit sproutschools.com.