I don’t know how close this is to reality, or if this will make sense to my readers. I confess that my position here is more based on personal experience than anything else, although I have also heard a lot of people express similar thoughts as regards to how they come to believe things.
My basic idea is that we don’t really “convert” to any belief, position or ideology. We adopt them because we realize that they fit what you could call our personality, our way of thinking and feeling. When we consider an idea, we recognize how much or how little it is in accord with our own personality and therefore we adopt or reject it. In essence, my view is that we are “born that way.”
However, we do change beliefs quite a bit. I think part of that is because we are simply not aware that certain positions even exist. I was an atheist since the age of seven but I simply did not know the word existed. From what I have observed, a lot of people started in life with a skeptical attitude towards religion, politics, life, but were not aware that the alternatives existed.
Another major issue is that alternative positions are slandered to such an extent that it can be hard to take them seriously unless one knows what they’re really about. If you are indoctrinated to believe that all atheists are amoral nihilists, that evolution says that two amoeba gave birth to a mouse and that life is a random process, that anarchists are all bomb-throwing nihilists, that abortion is hedonistic murder, that antinatalists are suicidal nihilists (well, you get the picture: anyone who disagrees with your personal values is portrayed as a nihilist), you’re not likely to take their ideologies seriously.
In all cases, I believe, the issue is in the information not being available or not being correctly presented, not in people not being persuaded. In practice, the line is blurred, so my idea may actually not mean that much. In order to correctly present atheism to fundamentalist Christians, you basically need to argue against the misconceptions they have come to believe, which involves persuasion.
People who are stuck with a fixed idea have set such a high barrier between themselves and their spiritual progress that they protest every step of the way, and make it extremely difficult or impossible for them to follow their true nature. There is a need for every person to accumulate information so that they can constantly improve.
I think this also has consequences for the way beliefs evolves as a whole. I think there are all kinds of people who naturally would follow all kinds of beliefs, but most of those beliefs either do not exist, are impossible to formulate, or are too obscure or discredited for people to follow them. So social conditions dictate whether a person’s natural dispositions will find fertile soil or not. For people who were predisposed towards Christianity, the Middle Ages were good times; for those who were predisposed towards, say, science, not so much (although they would perhaps have been attracted by astrology or alchemy, which were precursors of science).
Another reason why we just can’t create our own belief systems is that we generally only have intuitions, not articulated thoughts. At seven years old, I obviously hadn’t formulated an atheist cosmogony, atheological arguments, or anything of the sort. Before some kind of discovery process, all one has is intuition. Some particularly intelligent or motivated individuals may actually get somewhere with their intuitions and discover some truth that resonates with other people: those people may become thought leaders, if they are not killed or neutralized first.
Also, do not underestimate the importance of labels. People complain about labels on the basis of them dividing people, but consider that labels are extremely powerful stuff. Once you put a label on something, you start being able to think of it as an independent entity, as a unit of thought, which is just not possible otherwise. But when labels are not present, it is virtually impossible to analyze any potential belief system as anything but a set of disparate propositions. The label (rightly or wrongly) imposes coherence (in reverse, it is also true that a label creates the expectation of coherence where there is really none). It helps a body of knowledge grow by making it easy to find the beliefs and arguments related to it, and most importantly for the topic of this entry, permits easy self-identification and allegiance (ah yes, I am actually a ______, and yes, the argument that ______ does make sense to me).
It is not enough to think rationally or to have confidence in one’s reasoning: the flow of information is always crucial. Cults suppress access to information between members themselves, and between members and the outside, because this is the only way they can maintain the effectiveness of brainwashing. Brainwashing, hypnotism and indoctrination are fragile processes and need to be constantly reinforced with propaganda and censorship, because the native self-determinism of the person is always there, threatening to spring back up.
Suppressing self-determinism is very inefficient compared to twisting it for one’s own ends. In our modern societies, we are drowning in trivial entertainment; they don’t need to suppress the flow of information when they can just make people not want information in the first place (in short, Brave New World, not 1984). To make people want to learn more about important topics seems insurmountable, even things as easy to understand as the exploitation of the Third World by neo-liberalist policies, the Bible’s failure as a moral standard, or the inherent wrongness of jails and prisons, let alone more complex topics.