What are the different types of mental information? There are abstract concepts and objective facts - which relates to emotional information and numerical ability respectively. There is reasoning ability, and there is associative memory (which is basically linking similar objects together for faster recall). Reasoning ability doesn't necessarily relate to the amount or speed of someones memory - reasoning is something someone can think about by choice, while memory is less under someones control. A person could think of this or that in order to help remember something, however that wouldn't effect their measured I.Q. memory. Reasoning, however, is very subjective and someone could do a lot to increase reasoning ability.
What is subjective about reasoning information? It is that the information is about emotional material. Historical fact is about emotional material, and you could be considered to be using your reasoning ability when thinking about history. In fact, any idea related to human motivation is emotional and therefore subjective and subject to someone's reasoning ability. Unless someone uses reason to solve a math problem, or something objective, then reasoning is using emotional information and is subjective.