How we change what others think, feel, believe and do
Dictators know that information management is a critical part of controlling a population. They typically achieve this by managing the media so all that people see on the news is what the dictator wants them to see. Groups also use information control.
A common method of controlling information is to completely remove the person (or even the group) from any outside sources of information. They cannot control the media, so they remove themselves from it. Extreme groups lock themselves away in isolated buildings. They move to the country. They even move to other countries.
Another form of isolation is to demonize anything that is not approved by the group. People are forbidden to read banned texts or talk to people who might contradict what the group wants them to believe.
Information and education
When the person and the group are isolated from other influences, then information that supports the intended values and beliefs may be offered. In the information vacuum that is created by the isolation, people will grasp at whatever is offered them.
Managing the media
Controlling the information that is presented to people controls what they perceive as being normal. If one source of information presents something to a person, then they will consider it as being possible. If all information from all sources a person receives is consistent, then this will be taken as being true.
The media (newspapers, television, magazines, etc.) is generally considered to be neutral and consequently trustworthy. Managing what appears to be neutral and trustworthy sources can lead to powerful messages being transmitted that all move the person into the desired direction.
Managing the education system
When you control what is being taught, then you have a direct line into their beliefs and values. This is even more true for children. The Jesuits were famous for the saying 'Give me the child and I will give you the man'.
Running formal education sessions, where the person studies key texts and listens to the great and the wise sets up a teacher-learner dynamic with the teach as being all-knowing and the learner being subservient and accepting the teacher's truths.
One way that groups maintain control is to keep a very close watch on any dissent within the group. This is typically done through a system of outright spying and a system where informing on one another is considered normal practice, whereby any form of secrecy is framed as selfishness (even though the group leader has many).
Particularly when people are punished for keeping secrets, gossiping or showing any form or disagreement with the group and its leaders, they will hold back any such actions - and even the thoughts behind them. Groups can thus become highly conforming, but with an undercurrent of fear and repression.
Individuals may also be spied upon and information gathered about them before they join the group, and this used to help persuade them to join. Financial information is particularly interesting, especially if the group is planning to strip them of their assets.
When outside information has been removed, then the leaders of the group can define truth as whatever they want it to be. Values can be defined such that good and bad are presented as
When people do not know what to do, they look to other people. Group leaders can thus put people into confusing situations where the people do not know what to do, and hence look to the leaders for guidance.