Antithesis, Synthesis, Logic...
In a narrative the writer will often go to extensive lengths to explore and understand the logic of characters. Information may be derived from previous events, details and psychological conditioning of characters but it is often a question of where does the author stop displaying the information openly?
As a story unfolds, the writer may have all of the motivations penned but to keep the level of tension high they do not reveal these to their audience. When the main character and audience are left with the question of 'Why?' it should not be answered right away and in-truth, in a horror or suspense it probably should not be answered at all.
Stephen King once wrote that nightmares exist outside of logic and there’s little fun to be had in explanations; they’re antithetical to the poetry of fear.
Questions are the driving force in a story. The narrative thrives on the antithesis of knowledge that the primary characters hold regarding the primary question. The characters journey to answer the defining question is the heart of any piece. Every step that the characters take will yield its own questions but the singular driving question should never find its' answer until the story draws to a close.
The driving logic behind characters' actions and their motivations can assist the audience in connecting with the piece but it is the absence of that knowledge, that logic, that can make an emotion resonate through a story. In the end the audience will demand an answer and to a degree it must be given but there is more power to be found in withholding the entirety of that logic. A narrative is not about the logic, the explanations, it is a story about the quest for those explanations.
How much information do you give your characters? Your audience?