This is the basis of religion: bizarre rituals and beliefs to establish who belongs and who doesn’t. Conspiracy theory theory should really just focus on the cryptological effect and the intentionality/executive function weakness of humans. We need groups to establish a reliable intentionality through habitualization. Religions are powerful because they make people more useful to themselves. Religions are failing because advertising makes people believe they are consumers; useless to themselves, ergo, dependent on aristocracy’s systems(which is supported by religion’s promotion of blind belief in authority). People aren’t necessarily prone to believing in their group (ask any angsty teenager), but our systems of religion and civilization do condition us from birth to believe in our group’s behaviors and language as justified by ‘moral’ authority (even when that is an unsubstantiated claim eg The Invisible Hand).
Conspiracy theories work when people feel disconnected from their places and their usefulness (their actual value as living creatures). Any suggestion that something or someone is manipulating their life is easily believed and passed on to others when none are actively engaged in the operation of their own life (growing food, building shelter, caring for their own place). In other words, when people don’t have the means and experience of controlling where their next meal comes from and where they will sleep safely, they feel vulnerable and paranoid: perfect conditions for selling them crap they don’t need and politics that are against their own useful interests.