Coming back to the purpose of the thread - the psychology of why people become fundamentalists -
I would argue lots of people don’t become fundamentalists, but are conditioned to be fundamentalists from an early age. There are people who were brought up fundamentalists. As such, it not a case that they BECAME fundamentalists so much as they always were because they were not offered any other choice. If they were conditioned to think that way from an early age, and as they are taught it is right and true from an early age, and there are consequences of even questioning it, and they know of no reason why they should question it, it’s hardly surprising they embrace it. When they get older and are presented with challenges to their faith, they may begin to doubt, but they have been psychologically conditioned not to question from childhood because it is right and true, any doubts must be false, and giving serious consideration to challenges means you are not a ‘good Christian’ and you are displeasing God.
Overturning such is ingrained beliefs is no easy task, and people who leave religions that place a high demand of obedience on their members often have a pretty rough time. They also go through a crises of faith and can end up loosing their faith altogether. Therefore, accepting it and toeing the line is the easier option as not to do so has consequences that people find it difficult to deal with as they have been conditioned not to be able to. All in all, I would say such people have not become fundamentalists because they did not make a free and voluntary choice.
Of course there are people who do become fundamentalists, and I have a more cynical theory on that. Firstly, it appeals to them because they gain the approval of others. People with a low self-esteem will desire the approval of others, and fundamentalism gives them the opportunity to attain that as the approval of others features highly - ‘I believe everything, I’m trying to be good and do everything right’ will gain them the approval they desire. Secondly, you have a point about pride. Fundamentalism appeals to pride in that it tends to be very patriarchal. As such, it offers men who desire status, importance and have others to look up to them an opportunity to satisfy that pride that would not be afforded them in many mainstream Christian denominations. For example, in the JW’s an ‘elder’ does not have to be educated beyond knowing the ‘society’s’ literature inside out. It is my experience almost all men will be made ‘elders’ if they are enthusiastic, hang around long enough, and toe the party line thereby gaining the approval of others. Such men would probably go largely unnoticed in a mainstream Christian denomination. The same can be said of ‘pastors’ in Christian denominations outside the mainstream.
Women gain approval by toeing the line on patriarchy and ‘knowing their place.’ However, a hierarchy develops among women in that the wife of an ‘elder’ or ‘pastor’ is held in higher regard and as such, some assume an unofficial role of ‘elder’ or ‘pastor’ in their relationship with other women - perhaps to compensate for the fact they are so suppressed in other ways and it is their only outlet in coping with that suppression. One thing I noticed in the JW’s is women love to ‘teach.’ A significant percentage of the ‘door to door’ work and ‘bible studies’ is carried out by women, because the men are too busy being ‘elders,’ which enables them to feel good about themselves and gains that much wanted approval of others.
OK - that’s the theory. Now you can pick it apart.