“Coercion” is from DD’s TCS, not Popper. There is no comprehensive writing about it. My writing is your best bet. I have other articles you may not have seen like Fallible Ideas – Common Preferences
The poorly-explained Twitter threads and podcasts are from people who don’t know what they’re talking about (including about Popper or philosophy, not just TCS) and also are involved in the ongoing violation of my rights. Also, none of them are willing to defend their claims in debate.
The TCS founders, and various others involved, have gotten bad results trying to actually deal with kids. They purposefully mislead people about those results. I advise being wary of TCS. In Objectivist terms, they’re rationalists. They’re impractical armchair philosophers who think they’re so much cleverer than everyone else, but they’re not. They don’t know way better than tradition, convention, and other parenting views, and their radical, revolutionary ideas are risky and have actually done significant harm.
I built on DD’s idea and developed coercion further as an epistemological concept. It means, in short, failure at problem solving and getting stuck with no way forward that is OK with you. So you see no solution. (That includes no solution about the issue itself and also no solution about looking for solutions more and acting later. You’re out of time.)
Coercion usually involves external reality (including other people), but is always at least partly a matter of your own attitude and mindset. Regardless of external circumstances, there is a truth about how to best proceed, and you could be psychologically OK with proceeding that way since it’s best (as usual, use the contextual truth about what’s best to do given your knowledge, which is also objective, instead of the perfect truth of what you could do in the same situation if you were omniscient). This is sometimes very hard (e.g. if you’re being tortured) but usually pretty realistically achievable if you act/think rationally and know some general stuff about problem solving and thinking methods.
Sometimes people don’t mind physical pain sensations or even like them. It’s a matter of ideas and interpretations.
People suffer when there is a clash of ideas, e.g. they want to not feel the pain but do feel it.
You can see this as a clash of ideas against reality, but it’s actually our ideas about reality that are involved in the clash. We may be confused about reality, in which case, as far as psychology goes, it’s our own ideas about reality that matter rather than reality. E.g. if you lose a bunch of money, but think that you didn’t lose it, then you won’t be upset (for now). Of course being confused about reality will quickly run into concrete problems and that can be psychologically upsetting (e.g. if you’re wrong about your wealth, you may try to buy a car but people refuse to give you the car because you can’t actually pay).
A clash of ideas is, philosophically, a problem to be solved. People dislike that when they fail at problem solving (sometimes about tangential or meta issues, e.g. they are lazy so they get upset before even trying to solve X because of a different conflict between their laziness and the need to use effort to solve X). They fail to rationally resolve a conflict between ideas (and also fail to buy themselves more time to figure it out later – we are often OK with not knowing answers or stopping to think before proceeding, but there can be time limits at which point we actually want to reach a conclusion about something and we aren’t OK with more delays).
Active basically means it’s loaded in memory and you see how it’s relevant, so it’s affecting your psychology right now instead of something you’ve forgotten about or failed to connect to the current issue. People have tons of contradictions in their mind that they don’t even notice, so those don’t coerce them (though the contradictory ideas may lead to bad results in reality that the person then ends up coerced about – not noticing your contradictions is not safe). People compartmentalize, they’re hypocrites, they fail to integrate ideas, they don’t think in terms of principles, they forget things, etc.