Disenchanted with the testing industry’s focus on intelligence as a single, unitary quality that can be captured in a single number, Harvard psychologist Howard Gardner proposed in 1983 a radically different view of intelligence: the theory of multiple intelligences. Gardner’s theory is based loosely upon what is known so far about brain behavior relationships, and argues for the existence of several relatively independent kinds of human intelligence. Although he proposed seven of them to begin with, he acknowledges that the total number of intelligences has not been established, nor has their exact nature, so there may be more.
For an ability or aptitude to qualify as intelligence, it must fulﬁll several criteria, including the following:
- Potential isolation by brain damage: It must be localized somewhere in the brain, in such a way that it could conceivably be destroyed, or spared while other abilities are destroyed, by brain damage.
- Existence of savants and prodigies: The faculty is distinct enough to be spared under circumstances that render other areas of intelligence subnormal or to stand out among otherwise average performance.
- Distinctive developmental history: It follows a distinctive developmental progression, complete with milestones and critical periods.
- Evolutionary plausibility: It should serve some sort of plausible survival function, and/or share evolutionary antecedents with other organisms.
- Can be encoded in symbols: It should be possible to communicate the ability to others via symbols (such as mathematical formulas, words, musical notation, etc.).
Of the seven basic types of intelligence that Gardner initially proposed, three are well known even to traditional intelligence theorists: linguistic intelligence (the verbal intelligence that is a key part of the standard IQ tests), logical mathematical intelligence, and spatial intelligence. There are many well-established tests to measure those, unlike the remaining four intelligences:
- Interpersonal intelligence is the kind found in great political and spiritual leaders, along with all people who are skilled at understanding the intentions and desires of others, with the ability to inﬂuence and gain trust. Certainly, the large individual differences among people in this area are fairly easy to observe.
- Bodily-kinesthetic intelligence comprises the skills and abilities used by dancers, athletes, hunters, and others who rely on their ability to use their body to make a living. The evolutionary plausibility of this one is pretty straightforward: People who could hunt effectively and skillfully avoid predators certainly had an evolutionary advantage in humanity’s early days.
- Intrapersonal intelligence is essentially self-understanding, of the sort possessed by the great novelists and artists who are able to express feelings in a way that is universally understood.
- Musical intelligence is possessed by people who can easily learn to play an instrument or to compose music.
Gardner has recently added three more tentative candidates to his list of intelligences: naturalistic intelligence, spiritual intelligence, and existential intelligence. Naturalistic intelligence involves an ability to discern patterns in nature, such as was possessed by Charles Darwin and other great naturalists. Spiritual intelligence is a concern with religious and cosmic issues as they relate to one’s own development. Existential intelligence is simply a concern with the meaning of existence.
Many objections can be raised to the theory of multiple intelligences, on both practical and scientiﬁc grounds. Gardner’s critics frequently have difﬁculty seeing the difference between intelligence and an aptitude or ability. If any potentially isolatable ability is intelligence, is there any real limit to the number of intelligences that can be proposed? Does the concept of intelligence begin to lose its meaning as this happens? The list of aptitudes on which people can differ is potentially quite long. Also, several of the intelligences, especially the most recent three, are deﬁned so nebulously as to make them virtually impossible to study further. In a practical sense, even if one agrees, for example, to consider bodily-kinesthetic intelligence as a real thing, what implications does this have for the world of intelligence testing? Would it be possible to come up with a test that would be fair to both Michael Jordan and Mikhail Baryshnikov? Their areas of physical specialty are quite different from each other.
The real impact of Gardner’s theory has been in the educational profession. Many elementary schools are implementing curricula that are explicitly based on the idea of multiple intelligences, and this is probably a good thing. In a world where both the schools and their students are increasingly being judged against the narrow criterion of a standardized achievement test, an approach that respects and seeks to nurture a wider range of abilities can only be positive. Solid psychometric theory or not, Gardner’s multiple intelligences are a useful tool for reestablishing that there is more to human performance than is measured by standardized tests.
- Gardner, Howard. Frames of Mind: The Theory of Multiple Intelligences. New York: Basic Books, 1983.