Deikman, Arthur. The Wrong Way Home: Uncovering Patterns of Cult Behavior in American Society. Beacon Press, 1994.
It is entirely possible for perfectly intelligent, well-meaning people to be sucked into cults unawares, and it is very, very difficult for those same people to escape and nearly impossible to escape unharmed. This book explores the patterns of cult behavior we can see in American society and how and why well-intentioned people can be deluded by what the cult promises. I found this book to be rather dry and clinical, but an interesting read nonetheless.