In 1968, Robert Rosenthal and Lenore Jacobson told California teachers that a test had identified pupils about to “bloom.” These children, actually picked at random, gained more IQ points by the end of the year. But the gains were concentrated in first and second grade, and the test produced implausible scores. Meta-analyses find a real but small effect, close to zero when teachers have already known their pupils for a few weeks.
Remembering is not replaying a recording — it is rebuilding. Each time you recall a memory, it becomes temporarily malleable and can be altered before being stored again. That is why two people can sincerely remember the same event… differently.
In 2003, Johnson and Goldstein compared European countries. Where you must tick a box to become a donor, consent rates ranged from 4% to 28%. Where you're a donor by default unless you opt out, they topped 85%. People aren't more generous on one side; most simply stick with whatever option was chosen for them.