Marc “Animal” MacYoung’s Cults in the (Martial Arts) World is a thing of beauty and “sense”, as befits his whole great site No-Nonsense Self-Defense. Real-world, no-bullshit information that we should be teaching our children (and ourselves).
Note the universal application of his description of cults and cult-like behavior:
When it comes to cults, there is nothing simple about them. Cults have incredibly complex business/interpersonal/marketing/spiritual /psychological dynamics. However, there is one overriding element, making money.
There are many other great articles there. Surf around and sample. You might start with Self-Defense Explained.
(h/t In Mala Fide)