CrashCourse actually did a pretty good lecture about this a few months ago — basically, the difference between a cult and a religion is sorta granular, but there’s a few different checklists out there that you can use to discern the likelihood of something being a cult. The one in the video (developed by Dr. Roger J Lipton and the Cult Education Institute) goes:
A charismatic leader who offers validation and is believed to be the sole or primary source of truth in the world
Abuse (including, but not limited to: sexual abuse, financial abuse or labor exploitation)
Extreme paranoia about the outside world
No meaningful tolerance for questioning of practices and beliefs
No meaningful financial transparency (basically, can you determine where the money is really going?)
No meaning or viable exit strategy (if you want to leave, how easy is it to do so?)
The more boxes that get checked off, the more likely that an organization falls under the definition of a cult.
Take Mormonism, for instance. Mormonism expects its adherents to wear specific religious garments, but that’s not inherently cultish — many religions have religious garments without being cults, such as Muslim hijabs, Jewish kippahs or the Khalsa Sikh Pañj Kakār. Mormonism also lacks transparency about its religious temple ceremonies, but that’s not inherently cultish, either — many other faiths have closed practices as well, such as the Lakota (where only indigenous members of their communities may participate) or Haitian Vodou (which require an initiation ceremony before you may participate). However, Mormonism also checks off numerous other boxes on the cult list: there is a charismatic prophet believed to be God’s direct speaker on Earth, there is systematic financial and labor abuse via withholding saving ordinances from members who fail to pay a 10% income tithe to the church, there is extreme distrust of “the World” and “the Natural Man”, there is an intolerance for asking difficult questions or seeking non-Mormon sources, there is a notoriously-opaque financial system (the LDS church boasts a huge amount of capital and stock holdings, including investments in companies like Coca-Cola and Northrop Grumman), and it is extremely difficult to officially leave the church in both a legal and social sense. Accusing the Mormon church of being a cult based on its religious practices is about as effective as claiming that sugar is evil because Hitler once ate a chocolate bar, but analyzing it using an method devised by cult researchers does provide reasonable evidence to call it a cult… unless you’re my devoutly-Mormon father, who insisted that the similarities were “out of context” and that I oughta pray more to know the truth. Alas.
We could also apply the cult checklist to other organizations as well:
Is MAGA a cult? I’d argue that it meets at least 4 out of 6 of the criteria on the checklist — charismatic leader, extreme paranoia, intolerance to questioning and no meaningful financial transparency, with abuse is a likely addition considering the movement worships a rapist and a con artist — so it’d be reasonable to call it a cult despite not being a religion.
Is Catholicism a cult? That’s more debatable: they have a central figure and a recorded history of abuse, but the other four criteria are less cut-and-dry, so I’m not comfortable making any bold declarations here.
Are the Swifties a cult? Any answer here will see me cut to ribbons, so I plead the fifth.
The video also cautions viewers to remember that not all rhetoric that cults use are inherently evil — cults often utilize catchy mantras to maintain indoctrination, but “catchy mantras” are also used as slogans and calls to action for organizations that are both good and bad. Instead, it’s better to remain aware of when people are trying to manipulate you, then decide whether or not you still want to help. Not everything’s a conspiracy! When my wife says “dang, I could go for pizza right now, but I don’t wanna leave the house”, she’s trying to manipulate me into saying “alright, I’ll go get a pizza”, but I’m still very much a willing participant in the pizza-obtaining process. Human communication really all boils down to trying to get other people to do something you want them to do, and accepting that is an important step in learning how to interact with others in healthy ways.
Anyway good post OP, apologies for the lecture