It is relatively easy to identify thoughts and thinking errors. Change is reasonably easy but requires 2 parts.
1. Person wants to change the thought. They see it as a problem .
2. Break the habit. Thinking, like feeling and behaving are habitual. This takes effort as one has to remind self many times to think in the new ways, not the old ways. Research shows that it takes about 66 days (2 months) to break a reasonably strong habit. After that the new thinking has become habitual and the old thinking has stopped being habitual.
Beliefs are very resilient and resistant to change. Much harder to change than thinking as it is not just a habit it is also how we structure our personality. For instance racism is a belief system that a society sees as bad but the person’s own Child and Parent ego states may not see as bad. Our belief systems are in our bones and form part of who we see we are. They are part of our personality,
If one has a racist belief system one can never get rid of that once it is formed in childhood. It has become part of the Parent ego state and that can never be gotten rid of. You cannot get rid of part of your personality. What you can do is add in a new non racist belief system. Such a person then would have 2 belief systems one racist and one not racist. This person is always qualitatively different to the person who never formed a racist belief system in childhood. Such a person only has one non racist belief system.
Of course it works the other way as well. “Good” belief systems are also resilient and resistant to change. If a boy grows up with the belief system that women are good and equal then that is also hard to change. If an adult non sexist male looks at pornography that will never turn him into a misogynist. That belief system does not change that easily even if he looks at a lot of pornography.
One can obtain a new belief system by introjection. This of course requires the development of a relationship and then introjection over a long period of time making it much harder to change than a thinking pattern
The Adult ego state can modify the expression of a belief but of course it cannot change the belief. In Australia there has been a history of spectators at football games making racial slurs at players. This is now very forbidden and perpetrators suffer harsh consequences. The football powers to be now proudly say they have got racism out of football which is an absurd comment. Those with racists beliefs have not changed their beliefs all they have done is stop verbalising those beliefs at a football game. However this shows how the Adult ego state thinking can modify the expression of a belief but it does not change the belief. They don’t verbalise those racist thoughts as their Adult thinking says it is unwise to do so at football.
Those with a weaker Adult are more at the mercy of their beliefs than otherwise. They will find it harder to modify the expression of their belief systems. In this way one could say they will be more fundamentalist as they lack the ability to cognitively assess how they express their beliefs.