Reading intelligence in three layers
CHC theory is a framework for understanding intelligence in three layers. This way of thinking is also part of how intelligence tests such as the WAIS and WISC are interpreted.
At the highest layer, the third stratum, is the g factor. It is the general tendency that appears across multiple cognitive tasks. In testing, it is often estimated through FSIQ, or Full Scale IQ.
At the middle layer, the second stratum, are broad abilities. This is where abilities such as Gc (crystallized intelligence), Gf (fluid reasoning), Gv (visual-spatial processing), Gwm (working memory), and Gs (processing speed) are separated. When reading differences across a cognitive profile, this layer is central.
At the most specific layer, the first stratum, are narrower abilities such as vocabulary, inductive reasoning, mental rotation, and symbol search.
CHC theory is a framework for reading IQ as a combination of abilities, not only as one number. Even with the same overall IQ, a person with higher Gc and a person with higher Gf may have different strengths and different conditions that create load.
Five core abilities
CHC theory includes many broad abilities. In BrainTypeIQ, the main focus is on these five domains.
Gc (crystallized intelligence) - The ability to use vocabulary and knowledge for understanding, judgment, and expression. It supports grasping meaning through language, reading context, and connecting what you know to new information. See what Gc is for more detail.
Gf (fluid reasoning) - The ability to find relationships or rules in a new problem and reason through it in the moment. See what Gf is for more detail.
Gv (visual-spatial processing) - The ability to handle shapes, positions, directions, and three-dimensional images in the mind. See what Gv is for more detail.
Gwm (working memory) - The ability to hold information temporarily while using it to think. See what Gwm is for more detail.
Gs (processing speed) - The ability to judge visual information in a short time and respond accurately. See what Gs is for more detail.
What CHC theory changes
FSIQ alone does not always show differences across domains. Overall IQ is a useful entry point for seeing the general level, but it does not clearly show which areas are stronger or where load is more likely to increase.
For example, two people may have the same FSIQ even if one has high verbal comprehension and low processing speed, while the other has high fluid reasoning and more load in working memory. CHC theory makes this difference easier to read as a combination of abilities.
CHC theory in BrainTypeIQ
BrainTypeIQ is an online IQ test with 9 tasks that shows overall IQ and differences across the cognitive profile. Its structure uses CHC theory as a reference and separates the five domains of Gc, Gf, Gv, Gwm, and Gs.
It is not a substitute for a diagnostic assessment, but it can be an entry point for thinking not only about overall IQ, but also about the cognitive domains where strengths or load appear.