These threads take place in the setting of The Invention of Lying, with a few changes noted below.
The Invention of Lying is a modern-ish Earth-ish world populated by humans, except that: humans are not really capable of self-deceit to any meaningful degree, and they are not at all capable of lying, where you report something different than what you believe. This includes sarcasm, joking, fiction, lying by Grecian implicature, lying in text or in pictures, lying about your degree of confidence in something, etcetera. They are self-aware and well-calibrated: people who are below average at things will know it and say so.
They also compulsively provide full accurate context for behavior: If you have ulterior motives for a claim, like that you want people to buy your product, you tend to confess them out loud. If you wore your nicest outfit to impress a date you'll almost definitely tell the date "I wore my nicest outfit to impress you."
These compulsive behaviors do not prohibit 'concealing evidence that might lead someone to a true conclusion'. For example, a murderer might throw a body into a river in the hopes it won't be discovered to be a murder.
However, if the police ask them 'what did you do that evening?', they will say 'I got dinner, murdered Bob, and threw his body into the river in the hopes it wouldn't be discovered'.
Their not-lying isn't just acculturation; even after they've met people who tell contradictory stories in front of them, they won't be able to tell the contradictory stories themselves, or identify the contradiction.
Furthermore, in this setting, people believe everything that other people tell them, with whatever confidence the other person expressed in it, including believing all of the implications. They will change their minds if someone tells them something that contradicts something someone else told them. That includes information sourced from written and video records.
They won't just verbally agree with the new set of statements, they'll, for example, throw themselves off roofs if you tell them the building is burning. If you say something which would be shocking if true, it will be on the national news that night.
Changes from the movie:
In the movie, commercials are just a sad looking man standing next to the product telling you that you can keep buying it in stores. This feels psychologically implausible to me; I'm imagining something more like commercials are a sincere fan of the product saying "I like the product a lot! Only 1% of people like it as much as me, but even a 1% chance that you'll like it as much as I did might be worth $10 to you, and it's only $10!"
This setting doc will probably be updated as I see which things about the setting actually make it hard for people to run.
This is an open continuity; anyone can run a thread in it. Some of the threads might collide at some point.