Imagine a towering bookshelf and one of those sliding ladders. On the top shelves are the books related to highly g-loaded subjects (physics, math, classics, philosophy), and the more mainstream and accepted books are toward the center, with “fringe” stuff out toward the edges.
Having a higher IQ is like having a taller ladder, so’s you can reach higher shelves and read the more difficult books. Having a high associative horizon is like having a ladder that slides properly, so’s you can reach books farther into the periphery of the fields available to your ladder height. Conscientiousness means you read books in order, according to a predetermined plan. Depending on your personality, that plan may have been picked by an external authority or by internal forces.
Psychoticism has, instead, an element of caprice. A psychotic person picks books according to momentary whim, and reads them until interest subsides, and often does not finish them. Psychotic geniuses are therefore characterized by having a very strange distribution of knowledge, which is often specialized, and they often lack common knowledge (that is, the books within a narrow range on the lower shelves). This is not the same as lacking common sense or intelligence, but is rather due to the more pressing need to satisfy internal desires. Strong external stimuli (war, starvation, etc.) can produce neurotypical-like behavior in these folks.
Having low associative horizon can be mistaken for conscientiousness, because it restricts the range of books that may be read. If only ten books are within reach, the order in which they are read matters less.