The finding that changed how experience should be designed came from a study asking people to choose between different durations of cold water immersion. The results made no rational sense — and they explain a significant portion of why customer satisfaction surveys produce data that does not predict customer behaviour.

The cold water finding and what it established

Kahneman, Fredrickson, Schreiber and Redelmeier’s 1993 study gave participants two trials. Trial A: immerse a hand in 14°C water for 60 seconds. Trial B: immerse a hand in 14°C water for 60 seconds, then keep it immersed for an additional 30 seconds as the temperature slowly rose to 15°C — still uncomfortable, but marginally less so. Trial B contained all the pain of Trial A plus additional discomfort. By any objective measure, Trial B was worse. When asked which trial they would prefer to repeat, 69% chose Trial B.

The explanation is the peak-end rule. Retrospective evaluation of an experience is determined primarily by the average of the peak intensity — the most extreme moment, positive or negative — and the end intensity. Duration neglect follows directly: the length of an experience has surprisingly little effect on its retrospective evaluation compared to the peak and end moments. Trial B had a better ending. That was enough to make it the preferred choice despite being objectively longer and more painful.

The colonoscopy randomised trial: the commercial implication in miniature

Redelmeier, Katz and Kahneman conducted a randomised clinical trial with 682 colonoscopy patients. One group received the standard procedure. The other had the scope left in for an additional three minutes without movement at the end — creating a lower-pain ending than the standard procedure. The extended group retrospectively rated their overall experience as 10% less unpleasant and were 10% more likely to attend a follow-up procedure. The extension cost three extra minutes of mild discomfort and produced measurable improvement in both subjective experience rating and subsequent health behaviour.

The commercial translation is direct: a worse process with a better ending produces better overall evaluation and better subsequent behaviour than a better process with a worse ending. The last experience the customer has before leaving determines their retrospective evaluation more than the entire preceding experience. A checkout process that ends with a confused billing query, a customer service interaction that ends with unresolved frustration, or a product that ends its onboarding with a confusing final step — all will be remembered as worse than their total quality warrants.

The snapshot model: why duration does not determine satisfaction

Kahneman’s snapshot model explains the mechanism. The experiencing self lives through moments continuously, but the remembering self constructs a retrospective evaluation from a small number of representative snapshots — specifically the peak and the end. The remembering self does not sum moments across the full duration; it samples a small number of representative moments and constructs an evaluation from those samples. More moments do not produce more weight in the evaluation because they are simply not all sampled.

The business implication is counterintuitive: investment in extending the duration of positive customer experience does not proportionally increase customer satisfaction. A thirty-minute customer service interaction with a poor ending will be remembered more negatively than a five-minute interaction with a slightly mediocre middle followed by a genuinely positive resolution. The remembering self does not credit the extra twenty-five minutes of competent service against the poor ending.

The service recovery paradox as peak engineering

Customers who experience a service failure followed by an excellent recovery consistently evaluate their overall experience more positively than customers who experienced no failure at all — a finding confirmed by McCollough, Berry and Yadav in hotel contexts and replicated across multiple service industries. The peak-end rule explains this precisely. The failure creates a negative peak, but the excellent recovery creates a positive peak and a positive ending. The resulting retrospective evaluation is better than the undramatic experience that had no memorable peaks in either direction. Managing peaks — including deliberately creating positive peaks through exceptional responses to failure — is more valuable than maintaining consistent mediocrity throughout.

The pain of paying and why subscription pricing exists

Knutson and colleagues’ fMRI research identified the neural correlates of the pain of paying — the aversive insula activation associated with spending money. This activation was lower when payment occurred before the consumption experience than when it occurred during or after. Pre-payment means the experience ends with the positive consumption rather than with the aversive payment. Post-payment means the final moment is the aversive one. The widespread shift toward subscriptions, pre-payment, and all-inclusive pricing in the experience economy is not primarily about convenience — it is a structural implementation of end management, ensuring that the last experience the customer has is the consumption rather than the cost.

What airlines get systematically wrong

Airlines consistently rank among the lowest satisfaction-scoring consumer categories despite improving seat comfort, in-flight entertainment, and catering quality over the past decade. The peak-end analysis identifies the mechanism. The negative peak — a turbulent moment, a rude interaction, a delay announcement — dominates retrospective evaluation. The exit experience — deplaning, baggage claim, ground transport — is typically the most frustrating and least-managed stage of the journey, ensuring that the end is also negative. Airlines invest heavily in the middle of the experience while systematically underinvesting in the two moments that the rule identifies as the actual determinants of satisfaction. A passenger who has a comfortable flight but spends forty minutes waiting for bags will remember the journey as worse than one who had a slightly less comfortable flight and collected bags in five minutes.

Book worth reading on this

The Power of Moments by Chip Heath and Dan Heath is the most accessible business-applied synthesis of the peak-end rule and the practical design of memorable experience moments. The Heath brothers ground the research in case studies across healthcare, education, retail, and service design — showing how organisations have deliberately engineered positive peaks and endings to produce customer and employee experiences that are remembered as significantly better than their average quality warrants. For any entrepreneur designing a customer journey and trying to allocate investment toward the moments that will determine how the experience is remembered, this is the book that translates the Kahneman and Redelmeier research into specific design decisions with enough case study detail to make the translation immediately actionable..

If the dynamics described here are significantly affecting your wellbeing, speaking with a psychologist is the right next step. UK: Samaritans (116 123, free, 24/7). Mind (0300 123 3393). BACP: bacp.co.uk/search/Therapists. Crisis Text Line — text HOME to 741741 (US, UK, Canada, Ireland). International: internationaltherapistdirectory.com.

This article is for educational and informational purposes only. Sources: Kahneman, D., Fredrickson, B.L., Schreiber, C.A. & Redelmeier, D.A. (1993), When More Pain Is Preferred to Less: Adding a Better End, Psychological Science, 4(6), 401–405. Redelmeier, D.A. & Kahneman, D. (1996), Patients’ Memories of Painful Medical Treatments, Pain, 66(1), 3–8. Redelmeier, D.A., Katz, J. & Kahneman, D. (2003), Memories of Colonoscopy: A Randomized Trial, Pain, 104(1–2), 187–194. Kahneman, D. (1999), Objective Happiness, in Kahneman, D., Diener, E. & Schwarz, N. (Eds.), Well-Being: The Foundations of Hedonic Psychology, Russell Sage Foundation. Do, A.M., Rupert, A.V. & Wolford, G. (2008), Evaluations of Pleasurable Experiences: The Peak-End Rule, Psychonomic Bulletin & Review, 15(1), 96–98. McCollough, M.A., Berry, L.L. & Yadav, M.S. (2000), An Empirical Investigation of Customer Satisfaction after Service Failure and Recovery, Journal of Service Research, 3(2), 121–137. Knutson, B., Rick, S., Wimmer, G.E., Prelec, D. & Loewenstein, G. (2008), Neural Predictors of Purchases, Neuron, 53(1), 147–156. Heath, C. & Heath, D. (2017), The Power of Moments, Simon & Schuster. Eyal, N. (2014), Hooked, Portfolio. Kahneman, D. (2011), Thinking, Fast and Slow, Farrar, Straus and Giroux.