Intense Moments and Grand Finales: How Memories Are Made

You’re at a friend’s wedding reception. You’ve spent the afternoon on a terrace overlooking a beautiful beach, catching up with friends you haven’t seen for a while. Together, you watch one of the most beautiful sunsets you have ever seen. All is good. You head to the bar to buy a round of drinks. You wait patiently for the bartender to take your order. The person who has just been served turns clumsily into you, spilling a glass — a large glass — of red wine all down your outfit. Every single drop of that wine is soaking into your clothes. The sudden chill on your chest is a sharp contrast to the heat that now erupts on your face. A few choice words are exchanged. The bartender is forced to intervene. You storm off to the toilets to try (in vain!) to wash away a stain larger than Brazil….

If I were a betting man, I would wager that ten years after that wedding, the beautiful sunset wouldn’t be the thing that stands out in your memory – the glass of red wine would have seen to that. Or, more precisely, a phenomenon known as the peak-end rule would have. The peak-end rule — also known as the "peak-end memory bias" — helps to explain why our memories of events don’t necessarily represent the experience as a whole. We simply don’t have enough capacity to retain a detailed account of all our moment-by-moment experiences. Instead, our memory system works to characterise events based on an average of the most intense element (i.e., the "peak") and the most recently experienced element of the proceedings (i.e., the "end"). Other factors — such as how long the events lasted — don’t influence our memories to the same extent. For example, a single bite of the most delicious chocolate you have ever tasted (up there with Willy Wonka’s Whipple-Scrumptious Fudgemallow Delight) will live longer in your memory than munching on a full bar of Dreary Milk chocolate. This is referred to as "duration neglect."

Our memories are shaped by particular snapshots of the events that we experience.

Source: Lisa from Pexels / Pexels

Work on the peak-end rule was pioneered by Israeli American Nobel Prize winning psychologist Daniel Kahneman and colleagues. Kahneman et al. (1993) conducted three rounds of an experiment with 32 students based at the University of Chicago:

• In round 1, participants were instructed to keep their hand in water that was maintained at a temperature of 14 degrees Celsius for 60 seconds.
• In round 2, participants were instructed to hold their other hand in water maintained at a temperature of 14 degrees Celsius for 60 seconds, followed by 30 seconds at 15 degrees Celsius.
• In round 3, participants were given the option of choosing between repeating round 1 or opting to do round 2 again.

Importantly, the order of rounds 1 and 2 was altered across participants to ensure that the sequencing of the rounds didn’t influence the findings. Consistent with what the research team predicted; most participants (69%) preferred to repeat round 2. Even though they had to keep their hand immersed for longer, it seems that participants preferred round 2 because of the slight reduction in discomfort for the extra 30 seconds of that round. It’s not how long it lasted, but how it ended that determined participants’ preferences.

Since this pioneering study, the peak-end rule has been identified with experiences as diverse as tolerating chronic pain, exerting mental effort, enduring unpleasant sounds, and watching videos of varying picture quality. A major review of the research evidence, which incorporated findings from 112 different research publications, found clear support for the phenomenon (Alaybek et al., 2022, Alaybek et al., 2024). Retailers and service providers have been quick to harness the power of the peak-end rule. That’s why Ikea positions the hot-dogs and sweet-treats at the exit (hoping to end your experience on a high), dentists reward kids with a shiny sticker after a dental procedure, a yoga instructor concludes a class with a guided relaxation, and theme-park owners don’t stress about making you queue for 2-hrs for a ride that they know you will love.

Importantly, we can incorporate knowledge of the peak-end rule into initiatives that we might be planning to help engineer the most memorable moments. Knowing how your memories are created, can help you create better memories. Whether it’s a celebration for a loved one, customer service experience, an important but arduous work project, or a holiday itinerary, we can use an approach called "journey mapping" to be thoughtful about anticipating the peaks in intensity (both good and bad), and how we want those experiences to end. Of course, this won’t guarantee a wine-stain free night, but it might help to balance the memory of some of the trickier moments with the more enjoyable ones.