Intelligence is the ability of the brain to use deductive reasoning, to solve adaptive problems in the environment, in rapid and accurate ways. Deductive reasoning is “rule-based” reasoning that establishes cause-effect relationships in the world: a premise necessarily leads to a conclusion.
In terms of neural organization, most studies have found that brain organization involving processes described as “bigger, better, stronger, faster” are characteristic of intelligence. For example, normal humans who possess higher intelligence tend to have 1) larger brains, 2) thicker gray matter (the processing cells of the brain) in particular regions (e.g., frontal and parietal lobes), 3) better white matter connectivity (i.e., the wires that connect the processing nodes) between regions, and 4) more of certain chemicals in particular regions (e.g., N-acetylaspartate) serving multiple biological roles.
My 2007 study with Richard Haier summarized the neuroimaging research, finding that the integrity of a distributed network of regions, particularly within the parietal and frontal lobes, predicted performance on intelligence measures. This theory—called the Parieto-Frontal Integration Theory, or “P-FIT”—serves as the best current model of how intelligence is manifested in the brain.
Creativity is the ability of the brain to use abductive reasoning, to solve adaptive problems in the environment, in novel and useful ways. Abductive reasoning is hypothesis generation based on the best available evidence. It involves abstraction, metaphor, and approximation—making inferences from the best available information.
Before “rule-based” reasoning emerges, there must be “best guesses” about how the world works, and we believe that the brain has evolved to solve this “early” reasoning challenge. Some guesses are highly adaptive (i.e., useful) and become the next iPhone or great work of art; the vast majority are novel, but quickly fade from common use. Interestingly, with increased quantity of ideas comes a greater likelihood of having a “good” idea (Dean Keith Simonton’s “equal-odds rule”).
In the brain, we have found something quite different from what we find with intelligence; namely, that less is often better in terms of structure-function relationships. In particular regions of the brain, less brain tissue, less white matter integrity, and lower levels of biochemicals have been associated with higher creative cognition. (See “The Structure of Creative Cognition in the Human Brain” for a review.)
Since 2007, our research has been funded by the John Templeton Foundation, first with a grant entitled “The Neuroscience of Creativity”, and now under a more focused inquiry regarding “The Neuroscience of Scientific Creativity.”
Aptitudes are natural abilities to learn particular sorts of activities quickly and easily. These particular skills that the brain possesses interact with creativity and intelligence to produce individual strengths when someone solves problems in the environment.
For example, a person might have exceptional pitch discrimination (and be the son or daughter of musicians). If identified, that person could leverage this strength or aptitude toward school, work, or creative endeavors. Someone with exceptional pitch discrimination is going to have an easier time in musical fields, while someone without this aptitude (or with relatively low aptitude) will find such work relatively harder.
There are many aptitudes that can be reliably measured, including: number checking, quantitative reasoning, computational operations, number memory, tonal memory, pitch discrimination, rhythm memory, design memory, mental imagery, color perception, color discrimination, and manual dexterity—to name a few. We are working with the Johnson O’Connor Foundation to determine brain correlates of such aptitudes and how these aptitudes interact with creative cognition and intelligence. Importantly, we are beginning a study of twins to determine the genetic and environmental influences of such aptitudes as they interact with brain structure and function.