Oxytocin is a hormone that plays a key role in childbirth and breastfeeding. In 2005, a study in Nature reported that a nasal spray of it made people more trusting in an investment game. The press fell for the “love hormone.” But replications often failed, and in 2020 a large preregistered replication, co-authored by one of the original researchers, found no effect on trust.
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.