Changing ones mind about a subject

[Edwardo Piet]

I've always noticed it tends to take time to sink in. Many people look back and credit what changed their mind but since when does someone go from theist to atheist or vice versa in the middle of a debate or change their mind about creationism and believe in evolution immediately after given evidence? People do seem to take their time. I guess beliefs wouldn't be very helpful if they were shaken too easily, it's probably somewhat important for our survival for the human psyche to not be so unstable as to quickly change its beliefs. After all beliefs are what lead to actions. I guess beliefs are similar to habits in this way? Hard to break but also hard to make.