Back in the 1910s, engineer Maximilien Ringelmann noticed that men pulling on a rope each exerted less effort as the group grew. In 1974, researchers blindfolded volunteers who believed they were pulling with a team while actually alone: they pulled noticeably less hard. When individual effort becomes invisible, it shrinks. That's social loafing.
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.