In 2001, David Strayer and William Johnston had volunteers drive a simulator while talking on the phone. They missed more signals and reacted more slowly, whether the phone was handheld or hands-free. Listening to the radio or an audiobook, on the other hand, didn't hurt their driving. The problem isn't a busy hand, it's the attention swallowed up by the conversation.
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.