Multiple Intelligences Theory: The Eight Intelligences and How It Conflicts with IQ

The theory of multiple intelligences (MI theory), proposed by psychologist Howard Gardner in 1983, treats intelligence as several independent domains rather than one. It is widely known as the claim that 'there are intelligences IQ cannot measure,' but it conflicts with mainstream psychometric theory on an important point. This article sets the two side by side.

The eight intelligences Gardner proposed

MI theory divides intelligence into the following domains (seven originally, with naturalistic intelligence added later):

• Linguistic: understanding and manipulating language
• Logical-mathematical: logical argument and quantitative reasoning
• Spatial: grasping figures and spatial relations
• Bodily-kinesthetic: control and use of the body
• Musical: rhythm, pitch, and timbre
• Interpersonal: understanding others' intentions and emotions
• Intrapersonal: understanding one's own states
• Naturalistic: classifying objects in the natural world

The core of Gardner's claim is that these are mutually independent and cannot be reduced to a single general ability.

Where it conflicts with g and CHC theory

Mainstream psychometrics starts from the opposite observation. Collect performance across diverse cognitive tasks and they almost invariably correlate positively with one another — this 'positive manifold' is the basis for positing a general intelligence factor, g (see g factor and CHC theory).

CHC theory, the modern standard framework, is a hierarchy placing broad abilities — fluid reasoning (Gf), crystallized intelligence (Gc), short-term memory (Gsm), processing speed (Gs) — beneath g. The domains MI theory calls independent that correspond to linguistic, logical-mathematical, and spatial intelligence are already handled inside CHC theory, and they have repeatedly been shown to correlate strongly with each other.

The main criticisms

Criticism of MI theory centers on two points. First, the factor-analytic evidence for the eight intelligences being independent is thin. Measure them and the domains correlate, which undercuts the premise of independence.

Second, there is a definitional question about whether bodily-kinesthetic and musical intelligence should be called intelligences at all; critics argue they are better described as talents or abilities. Gardner himself acknowledges the line is a terminological choice while maintaining the framework on the grounds of its usefulness in education.

Do not conflate it with the learning-styles myth

MI theory is frequently conflated with the claim that teaching to a student's learning style — visual, auditory, and so on — improves outcomes. That matching hypothesis has not found consistent support in controlled experiments.

Gardner himself has explicitly rejected the conflation. MI theory suggests that presenting the same content through multiple entry points deepens understanding; it is not the claim that each person has a dedicated way of being taught.

How to take it in practice

MI theory's value lies more in its educational perspective than in measurement theory. IQ tests do primarily measure territory relating to Gf and Gc, and it is simply true that they do not measure interpersonal skill or physical technique. In that sense the point that 'IQ is not everything' is correct; emotional ability is covered in EQ versus IQ.

Still, within the range that can be measured, cognitive ability has a real structure and that structure carries practical information. Look past the composite at the domain-by-domain unevenness and you can see which kind of reasoning you are strongest at.

Measure the part that can be measured

BrainRank's free IQ test scores 20 questions across spatial reasoning, pattern recognition, logical reasoning, and classification (about 10 minutes) domain by domain. It does not measure all eight of MI theory's domains, but for the core of what CHC theory calls fluid reasoning (Gf) it produces an estimate on the mean-100, SD-15 scale along with a domain profile.