The Peak–End Rule

The classic study: hold your hand in 14°C water for 60 seconds. In another trial, the same 60 seconds, then the water is warmed slightly (15°C) for 30 more. Longer, and more total discomfort.

Asked which to repeat, most chose the longer one.

Because of how it ended. The slightly less cold last thirty seconds improved the "end", and the memory of the whole was rewritten. Total suffering did not register.

Kahneman distinguishes the experiencing self from the remembering self. The first lives every second; the second takes home just two points — the peak and the end.

Duration is nearly ignored. A two-hour film and a four-hour one compress to the same two points in memory. This is called duration neglect.

So a bad experience with a good ending becomes "not bad, actually", and a good one with a bad ending becomes "ruined".

Design the ending. Put the thing you most look forward to on the last day of the trip. End the workday with fifteen minutes of tidying and notes, so it closes with a sense of a line drawn. With people, mind the parting sentence.

Build one peak. A short experience with one strong moment beats a long one with a good average. Bet on one thing rather than packing the schedule.

The games on this site put the most work into the result screen for the same reason: the last screen, not the sixty seconds before it, decides whether you play again.