Peak-End Rule
The peak-end rule is the claim that a finished experience is judged afterwards from two moments, the most intense one and the last one, rather than from the whole of it. The finding is Barbara Fredrickson and Daniel Kahneman's, from 1993, with Fredrickson as first author, and almost every popular account credits it to Kahneman alone. The correction that matters most is not about names, though. When 174 separate results were pooled, the peak and the end together did predict how an experience was rated, and they did no better than the plain average of the whole thing. So the popular version, that the middle gets thrown away, is not what the evidence shows. What gets thrown away is the clock.
What it is
The everyday form of the claim is familiar. A holiday is remembered by its best afternoon and its last evening. A procedure is remembered by how much it hurt at its worst and how it felt as it finished. Total time drops out.
The credit, stated properly, because this site got it wrong twice. The vault first recorded this as Kahneman's. On 2 September 2026 it was corrected to Redelmeier and Kahneman, on the strength of the colonoscopy work, which fixed the famous-name problem and introduced a dating problem: Redelmeier's papers are the medical demonstrations and they come later. The paper that establishes duration neglect and the snapshot model of remembered experience is Fredrickson and Kahneman, 1993, three years before the colonoscopy study. Both corrections are logged in the open, because a publication that criticises other people's attribution and then quietly fixes its own twice is not doing the thing it claims to do.
Kahneman is first author on one of the four. He is the name attached to all four in popular writing.