Contemporary certified IQ tests, and the widely-lauded international IQ tests, are based partially upon the theory of multiple intelligences. This groundbreaking theory, written and explored by the scientist Howard Gardner, identifies and distinguishes no less than nine types of intelligence, each of which can be seen in the general populous.

Gardner argued that while not everybody, and indeed very few, would possess all the nine types of intelligence in a fully-manifested or particularly noticeable way, they each are present in the human brain to a larger or lesser degree. We can see evidence of this in ourselves as much as in the people we surround ourselves with; most people are aware of their intellectual and cognitive strengths and weaknesses.

Gardner’s nine intelligence types are as follows:

• Linguistic Intelligence: this is the ability to write, read, listen, and speak. The vast majority of people possess a degree of linguistic intelligence, and those who are gifted orators, multi-linguists, translators, or widely read will display greater levels of this intelligence type.
• Spatial Intelligence: simply the ability to accurately orient oneself within a space, or envision imaginary spaces and how they interact in two or three dimensions.
• Logical-Mathematical Intelligence: the ability to solve logic puzzles, calculate problems, deal with numerical sequences, and think in a reasoned and scientific manner.
• Musical Intelligence: the ability to learn musical instruments, sing and identify rhythm, harmony, and melody, and be able to compose, read, and analyse music.
• Bodily-Kinesthetic Intelligence: the ability to coordinate the body and control one’s movement in an intentional manner. Dancers, sportspeople, and surgeons, for example, would need high levels of this intelligence type.
• Interpersonal Intelligence: this intelligence type involves understanding and interpreting (as well as responding to) both the verbal and non-verbal behaviours displayed by those around them.
• Intrapersonal Intelligence: simply the ability to meditate and reflect on one’s own actions and thoughts, and to understand and respond to them in a constructive or analytical manner.
• Naturalist Intelligence: being able to categorise and recognise items, objects, and phenomena in the natural world or in one’s immediate environment.
• Existential Intelligence: the ability to recognise and determine one’s own position in relation to the subject of human existence. Essentially, to be able to philosophise on subjects of life and death, and of the meaning of existence itself.

The Connection Between Multiple Intelligence Theory and IQ Tests

As is perhaps evident from these descriptions, most IQ tests – and certainly all certified IQ tests – are unable to gain conclusions about the majority of these intelligence types. For example, it would be all but impossible to run a standard IQ test which measures musical intelligence or existential intelligence, among many others.

Most IQ tests will deal with the first three of Gardner’s multiple intelligences, as these overlap with what is most commonly identified as signifiers of general intelligence, and they are the types which can most easily and consistently be tested.