The peak–end rule is an elaboration on the snapshot model of remembered utility proposed by Barbara Fredrickson and Daniel Kahneman.
This model dictates that an event is not judged by the entirety of an experience, but by prototypical moments (or snapshots) as a result of the representativeness heuristic.
Fredrickson and Kahneman theorized that these snapshots are actually the average of the most affectively intense moment of an experience and the feeling experienced at the end.
A 1993 study titled "When More Pain Is Preferred to Less: Adding a Better End" by Kahneman, Fredrickson, Charles Schreiber, and Donald Redelmeier provided groundbreaking evidence for the peak–end rule.
Against the law of temporal monotonicity, subjects were more willing to repeat the second trial, despite a prolonged exposure to uncomfortable temperatures.
Kahneman et al. concluded that "subjects chose the long trial simply because they liked the memory of it better than the alternative (or disliked it less).
"[3] Similarly, a 1996 study by Kahneman and Redelmeier assessed patients' appraisals of uncomfortable colonoscopy or lithotripsy procedures and correlated the remembered experience with real-time findings.
They found that patients consistently evaluated the discomfort of the experience based on the intensity of pain at the worst (peak) and final (end) moments.
One underwent a colonoscopy procedure wherein the scope was left in for three extra minutes, but not moved, creating a sensation that was uncomfortable, but not painful.
As a consequence, negative occurrences in any consumer interaction can be counteracted by establishing a firmly positive peak and end.
This can be accomplished through playing music customers enjoy, giving out free samples, or paying a clerk to hold the door for patrons as they leave.
As Scott Stratten has suggested, "A really great salesperson who helps with an exchange can erase negative experiences along the way.
They discovered that steep discounts could permanently erode demand in the future, as lowest prices remain salient in the memory anchoring process.
They argued that, for sequences of binary events (such as workers being repeatedly assigned to do tasks that are either hard or easy), streaks are the psychological analogue of peaks.
In 2006, a study was carried out at the University of Canterbury in Christchurch, New Zealand, analyzing the implications of the peak–end rule on the perceived happiness experienced on vacations.
Kahneman claims that "it is safe to assume that few patients will agree to expose themselves to pain for the sole purpose of improving a future memory".
A study by Hoogerheide and his team analyzes the effects of the peak-end rule in children's experience of receiving peer assessments.
The result shows that the peak-end rule likely influences children's perception and memory of the assessment as well as their learning outcomes and motivation.
Based on the result, Hoogerheide advises that teachers should structure the feedback by ending with the best part of the assessment.
Therefore, in order to maximize customer satisfaction, higher-priced restaurants should put their best food in front of the consumer first.
The effect of the peak-end rule in eating behavior also depends on personal factors such as self-restraint level on food choice.
[20] Critiques of the peak–end rule typically derive from its conflation of a complex mental evaluation into a simplistic framework.