Like in some cults of Christianity, they are taught to marry real early, legally, they like to have them married at exactly at 18 or their parents sign some paper saying they can marry at like 16 or something like that.
So why do people like to marry the 15 year olds?
Because they are compliant and usually have not developed any sense of self by that age. They are easier to lie to about "love" because they are still innocent enough to believe that an abuser really loves them.
It could be from a number of things. Religion, culture, pleasure and what you think is right and wrong. Some people believe that you should marry and have as many kids as you can to support reproduction. Some people believe that girls turn into women at the age of 16. Other's believe it's 18. And people like me, believe it's when you hit puberty. Some people marry young girls, and even have MULTIPLE wives, for the simple fact of pleasuring themselves, or because it is a tradition from where they came from.
That's because most cults (especially religious ones) are founded and/or led by a sex pervert, addict, or some other type of sexual wacko. Examples are: Joseph Smith, Jim Jones, and David Koresh.
Because there is something mentally wrong with them.
bunch of freaks