Emotions have quite a simple mechanism. Recognise a pattern -> fire off a response. The difference in reaction between people comes from the difference in the set of recognisable patterns and emotional responses tied to them. There are some common ones, like prediction violation you are talking about. And these patterns can also be overwritten if needed — thus removing undesired emotional response.
On top of that, we may or may not engage in conscious reasoning.
All of the above will create unique behaviour. :)