Peak–end rule end. The effects of the duration of an experience upon retrospective evaluation are extremely slight. Fredrickson and Kahneman labeled this phenomenon "duration neglect". The peak–end rule is applicable only when an experience has definite beginning and end periods. 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. Participants were subjected to two different versions of a single unpleasant experience. The first trial had subjects submerge a hand in 14 °C water for 60 seconds. The second trial had subjects
Cope's rule Cope's rule Cope's rule, named after American paleontologist Edward Drinker Cope, postulates that population lineages tend to increase in body size over evolutionary time. It was never actually stated by Cope, although he favoured the occurrence of linear evolutionary trends. It is sometimes also known as the Cope-Depéret rule, because Charles Depéret explicitly advocated the idea. Theodor Eimer had also done so earlier. The term "Cope's rule" was apparently coined by Bernhard Rensch, based on the fact that Depéret had "lionized Cope" in his book. While the rule has been demonstrated in many instances, it does not hold true at