Psychology Definition:

A general term encompassing various mental abilities, including the ability to remember and use what one has learned, in order to solve problems, adapt to new situations, and understand and manipulate one’s environment.


Intelligence, in psychology, the general mental ability involved in calculating, reasoning, perceiving relationships and analogies, learning quickly, storing and retrieving information, using language fluently, classifying, generalizing, and adjusting to new situations. Alfred Binet, the French psychologist, defined intelligence as the totality of mental processes involved in adapting to the environment. Although there remains a strong tendency to view intelligence as a purely intellectual or cognitive function, considerable evidence suggests that intelligence has many facets.

Early investigations into intelligence assumed that there was one underlying general factor at its base (the g-factor), but later psychologists maintained that intelligence could not be determined by such a simplistic method. Raymond Cattell argued that intelligence can be separated into two fundamental parts: fluid ability and crystallized ability. Fluid ability is considered innate, basic reasoning skill, while crystallized intelligence is the information and skills that are acquired through experience in a cultural environment. Other psychologists have further divided intelligence into subcategories. Howard Gardner maintained (1985) that intelligence is comprised of seven components: musical, bodily-kinesthetic, logical-mathematical, linguistic, spatial, interpersonal, and intrapersonal. J. P. Guilford tried (1982) to show that there are 150 different mental abilities that constitute intelligence.

It is generally accepted that intelligence is related to both heredity and environment. Studies done on families, particularly among identical twins and adopted children, have shown that heredity is an important factor in determining intelligence; but they have also suggested that environment is a critical factor in determining the extent of its expression. For instance, children reared in orphanages or other environments that are comparatively unstimulating tend to show retarded intellectual development. In recent years, controversy regarding intelligence has centered primarily around how much of each factor, heredity and environment, is responsible for an individual's level of intelligence.

Nature versus Nurture and Intelligence

The hottest argument in the Nature vs. Nurture debate is the concerns with intelligence.  What causes the differences in intelligence?  Is it all genetics or does our environment have something to do with it?  Overtime evidence has shifted back and forth on the pendulum of opinion.




The Historical Trends in the Nature versus Nurture Debate

Mid 1800’s through early 1900’s

During this time period the opinion was that an individuals personality, behaviour, and intelligence was because of nature.  Thanks to Mendel and Darwin and the idea of inheritance and natural selection the belief that genetics moulded the individual continued.

In 1869 Francis Galton observed gifted individuals and in his book Hereditary Genius:  Its Laws and Consequences he stated that the gifted individuals tended to come from families which had other gifted children.

Galton made the observation that it would be “quite practicable to produce a high gifted race of men by judicious marriages during several consecutive generations.”  This is known eugenics.  He was truly convinced that “intelligence must be bred, not trained.”

1920’s and 1930’s

Following the first World War a reanalysis of the mass of intelligence tests began.  This challenged the idea that intelligence was linked genetically to linked to racial differences.

Example- There were Blacks in Illinois that had a higher IQ than whites from 9 different southern states.

Focus is now turning away from intelligence, genetics, and race.  The result of this was psychologists from this time period began to believe in the environmental perspective.

1940’s –1990’s

1940’s- After some backlash individuals began to accept both views, the nature and the nurture.  Although they believed that neither were the reasons for behaviour, social problems still continued.

1960’s- the focus was no longer on the individual, but on society for social problems.  To try to address this problem special schools were developed to ensure an individuals schooling improved, and welfare was created to help with poor living conditions.

More Recently

The creation of “The Bell Curve.”  In the publics eye this again suggested that nature is the reason for intelligence.

“individual’s intelligence- no less 40% and no more than 80% was inherited genetically from his or her parents” Manolakes (1997), 235

Bell Curve also suggests that genetics not only effects an individuals IQ, socio economic status also has an effect.

This created a number of reactions and backlash.  It also re-ignited the nature vs nurture debate.

Evidence for “Nature”

Study completed on twins by Thomas Bouchard from the University of Minnesota proves that intelligence is connected to genetics.

During his study Bouchard collected data from a number of twins that were raised separately.  Other studies were completed on adopted individuals and siblings and twins that were raised in the same home.  IF your put the results together it would look like this:

·        Same person tested twice- 87%

·        Identical Twins brought up together- 86%

·        Identical Twins brought up apart- 76%

·        Fraternal Twins brought up together- 55%

·        Biological siblings living together- 47%  apart- 24%

·        Parents and children living together- 40%  Apart- 31%

·        Adopted children living together- 0%

·        Unrelated people apart- 0%

Ridley, 1999, p.83[ the number is a percentage correlation.  Attach section of Ridley’s book.

This Data provides evidence that the environment has as little as 10% responsible for IQ.

It is believed that intelligence is fixed for life around the age of 5 years old.  The environments influence on the IQ has a limited time span.

Evidence for “Nurture”

During the 1980’s James Flynn observed that IQ was on the rise in all countries.   He believes that it is the increase of visual images.  HE collected his information from adoption studies, nutrition studies, and educational intervention studies.

Today-  this is a debate that is still continuing- there are still some that believe that our intelligence is due to our genetics, while others still argue that it is mainly due to the environment.  From the mixture of evidence this debate will most likely continue.  Most psychologists and sociologists now believe that both nature and nurture affect our intelligence, but the pendulum swings more towards nature.  

There are a number of things that varies intelligence:

·        Birth Order

·        Birth Weights

·        Height

·        Number of Siblings

·        Infant malnutrition

·        Father’s profession

·        Parental ambition

·        Mother’s education

·        Number of years in school

·        Father’s economic status

·        Social group of parental home

·        Average TV viewing

·        Average book reading

·        Degree of Parental rigidity

·        Degree of authority

·        Age

·        Mental disease

·        Self-confidence according to attitude scale measurement

·        Degree of authority

·        Alcoholism

·        Emotional adaptation


ERIC Identifier: ED385605


Intelligence has been defined and studied under a number of different rubrics, among them individual differences, cognitive abilities, and aptitudes. Probably the most influential developments in our recent understanding of these concepts have come from educational and psychological researchers associated with cognitive psychology. Three of those individuals, Robert Sternberg, Howard Gardner, and John Horn serve as a representative sample of researchers who have made significant gains in our current conceptions of intelligence. In the following paragraphs I briefly summarize each one's conceptualization of intellectual abilities.

Robert Sternberg. Sternberg's (1985) theory of intelligence contains three subtheories, one about context, one about experience, and one about the cognitive components of information processing. The contextual subtheory attempts to specify what would be considered "intelligent" in a given culture or context. According to Sternberg, culturally intelligent behavior involves either adapting to one's present environment, selecting a more optimal environment, or reshaping one's current environment. The experiential subtheory claims that the expression of any intelligent behavior will be a function of the amount of experience one has with the particular class of tasks being tested. According to Sternberg, intelligence is best demonstrated when the task is relatively novel or unfamiliar. The componential subtheory describes the cognitive structures and processes that together produce intelligent behavior. Sternberg proposes three general types of processes: metacomponents (which control and monitor processing), performance components (processes that execute plans), and knowledge acquisition components (which encode and assemble new knowledge). As a whole, the triarchic theory claims different aspects or kinds of intelligence (e.g., academic, practical).

Howard Gardner. One of the most popular recent views of intelligence, at least among practitioners, has come from Gardner (e.g., Gardner & Hatch, 1989). He proposes a theory of multiple intelligences in which he claims there are seven relatively independent intelligences. Those intelligences are logical-mathematical, linguistic, musical, spatial, bodily-kinesthetic, interpersonal, and intrapersonal. Additionally, Gardner recognizes that one's experiences will influence the degree to which each of the intelligences can be expressed. Thus, rather than characterizing an individual's intelligence by a single test score, Gardner argues for determining the profile of one's intelligences, taking into account culturally valued activities that can be expressed in a familiar context. Accordingly, this view suggests the need for new forms of assessment. Gardner and his colleagues have been working on versions of new, more authentic assessment tools for the past 8 years. The results have been mixed. For a critique, the interested reader should see Sternberg (1991).

John Horn. Along with his advisor, Raymond B. Cattell, John Horn has developed a theory of intelligence that specifies two broad factors, fluid abilities and crystallized abilities, along with numerous specific factors that support the general ones. Fluid intelligence represents one's ability to reason and solve problems in novel or unfamiliar situations. Crystallized intelligence, on the other hand, indicates the extent to which an individual has attained the knowledge of a culture. According to Horn (1989), the Gf - Gc theory can also be thought of as a theory of multiple intelligences because of the relative independence of fluid and crystallized abilities (characterized by distinctly separate patterns of covariation). Horn also argues that the expressions of these abilities "... are outcroppings of distinct influences operating through development, brain function, genetic determination, and the adjustments, adaptations, and achievements of school and work." (Horn, 1989, p. 76)


An important development in our understanding of intelligence, is the near universal agreement among researchers that at least some aspects of our intellectual abilities depend heavily on our experiential histories. This acknowledgement should be clear in the three theories summarized above. Each one recognizes the inseparability of experience from intellectual ability. This position stands in stark contrast to the one that holds that intelligence tests measure - or ought to measure - one's innate capacity. Admitting that experience influences one's performance on an intelligence test severely undermines the innate capacity notion, unless one adopts the weaker position that intelligence is a measure of one's innate capacity to learn. In either case, the logical position to assume is that any theory that attempts to explain individual differences in intellectual abilities must include a learning subtheory as part of it.

A recent volume edited by Ackerman, Sternberg, and Glaser (1989) presents several current approaches that integrate information processing theories of learning with theories of individual differences in abilities. Two widely acknowledged views have come from Ackerman (e.g., 1993) and Lohman (1989; 1993). The next two paragraphs briefly summarize these researchers' views.

Phillip Ackerman. Ackerman (1993) has adapted aspects of John R. Anderson's theory of cognitive skill acquisition (e.g., Anderson, 1983) and coupled it with a theory of intellectual abilities proposed by Marshalek, Lohman, and Snow (1983). The integration has produced a hybrid theory which claims that as learning occurs, intellectual differences are reduced for tasks that have a consistent problem-solving structure. In contrast, intellectual differences become magnified for tasks that have variable (novel?) problem-solving structures. In other words, with practice peoples' intellectual abilities will be either similar or different, depending on the nature of the mental processes required to solve different types of problems.

David Lohman. Lohman (1989; 1993) has coupled information processing theories of learning (e.g., Anderson, 1983) with the Gf - Gc theory (e.g., Horn, 1989) in order to characterize the relation between learning and intelligence. It has been known for some time that crystallized intelligence was the product of the acquisition of knowledge (i.e., experience). However, recently Lohman (1993) has argued persuasively that fluid intelligence (i.e., the ability to reason in novel situations) may also be amenable to learning. In fact, he espouses that schools would benefit from direct instruction and testing of fluid abilities. 

According to Howard Gardner, as presented in his book Frames of Mind: The Theory of Multiple Intelligences, human intelligence has the following characteristics:

The following principles are a condensation of J. Keith Rogers and based upon his study of Howard Gardner's theory:

  1. 1.     Intelligence is not singular: intelligences are multiple.
  2. 2.     Every person is a unique blend of dynamic intelligences.
  3. 3.     Intelligences vary in development, both within and among individuals.
  4. 4.     All intelligences are dynamic.
  5. 5.     Multiple intelligences can be identified and described.
  6. 6.     Every person deserves opportunities to recognize and develop the multiplicity of intelligences.
  7. 7.     The use of one of the intelligences can be used to enhance another intelligence.
  8. 8.     Personal background density and dispersion are critical to knowledge, beliefs, and skills in all intelligences.
  9. 9.     All intelligences provide alternate resources and potential capacities to become more human, regardless of age or circumstance.
  10. 10. A pure intelligence is rarely seen.
  11. 11. Developmental theory applies to the theory of multiple intelligences.
  12. Any list of intelligences is subject to change as we learn more about multiple intelligences.

According to Howard Gardner, as presented in his book Frames of Mind: The Theory of Multiple Intelligences, human intelligence has the following criteria:

According to Howard Gardner, as presented in his book Frames of Mind: The Theory of Multiple Intelligences, "it becomes necessary to say, once and for all, that there can never be, a single irrefutable and universally accepted list of human intelligences." pg.60

Though an exhaustive list of every intelligence may not be possible, identifying intelligences is important for at least two reasons:

Linguistic Intelligence

The following definition is an abbreviation and adaptation by J. Keith Rogers and based upon his study of Howard Gardner's theory:

Linguistic intelligence (or verbal-linguistic) is the ability to use with clarity the core operations of language. People with linguistic intelligence have a sensitivity to the meaning of words--the capacity to follow rules of grammar, and, on carefully selected occasions, to violate them. At a somewhat more sensory level--a sensitivity to the sounds, rhythms, inflections, and meters of words--that ability which can make even poetry in a foreign tongue beautiful to hear. And a sensitivity to the different functions of language--its potential to excite, convince, stimulate, convey information, or simply to please.

People such as poets, authors, reporters, speakers, attorneys, talk-show hosts, politicians, lecturers, and teachers may exhibit developed linguistic intelligence.

Logical-Mathematical Intelligence

The following definition is an abbreviation and adaptation by J. Keith Rogers and based upon his study of Howard Gardner's theory:

Logical-Mathematical intelligence is logical and mathematical ability as well as scientific ability. Abstraction is fundamental, reasoning is complex, and problem-solution is natural. Order and sequence are significant. There is a drive to know causality as well as the explication of existence.

People such as mathematicians, engineers, physicists, researchers, astronomers, and scientists may exhibit developed logical-mathematical intelligence.

Intra-Personal Intelligence

The following definition is an abbreviation and adaptation by J. Keith Rogers and based upon his study of Howard Gardner's theory:

Intra-Personal intelligence is the ability to form an accurate model of oneself, and to use that model to operate effectively in life. At a basic level, it is the capacity to distinguish feelings of pleasure from emotional pain and., on the basis of such discrimination, to become more involved in or to withdraw from a situation. At the most advanced level, interpersonal intelligence is the capacity to detect and to symbolize complex and high differentiated sets of feelings.

People such as some novelists, therapists, sages, psychologists, and philosophers may exhibit developed intra-personal intelligence.

Inter-Personal Intelligence

The following definition is an abbreviation and adaptation by J. Keith Rogers and based upon his study of Howard Gardner's theory:

Inter-personal intelligence is the ability to notice and make distinctions among other individuals and, in particular, among their moods, temperaments, motivations, and intentions. Examined in its most elementary form, the inter-personal intelligence entails the capacity of the young child to detect and discriminate the various moods of those around them. In an advanced form, it permits a skilled adult to read the intentions and desires--even when those desires have been hidden--of many other individuals and, potentially, act upon this knowledge.

People such as politicians, religious leaders, and those in the helping professions may exhibit developed inter-personal intelligence.

Musical Intelligence

The following definition is an abbreviation and adaptation by J. Keith Rogers and based upon his study of Howard Gardner's theory:

Musical intelligence (or Musical-rhythmic) is the ability to use the core set of musical elements--pitch, rhythm, and timbre (understanding the characteristic qualities of a tone). There may be a hierarchy of difficulty involved in various roles--composition, performance, listening.

People such as singers, composers, instrumentalists, conductors, and those who enjoy, understand, use, create, perform, and appreciate music and/or elements of music may exhibit developed musical intelligence.

Spatial Intelligence

The following definition is an abbreviation and adaptation by J. Keith Rogers and based upon his study of Howard Gardner's theory:

Spatial intelligence (or visual-spatial) is the capacity to perceive the world accurately, and to be able to recreate one's visual experience. It entails a number of loosely related capacities: the ability to recognize instances of the same element; the ability to recognize transformations of one element in another; the capacity to conjure up mental imagery and then to transform that imagery; the ability to produce a graphic likeness of spatial information; and the like. A person with a good sense of direction or the ability to move and operate well in the world would indicate spatial intelligence.

People such as sailors, engineers, surgeons, sculptors, painters, cartographers, and architects may exhibit developed spatial intelligence.

Bodily-Kinesthetic Intelligence

The following definition is an abbreviation and adaptation by J. Keith Rogers and based upon his study of Howard Gardner's theory:

Bodily-Kinesthetic intelligence is control of one's bodily motions and the ability to handle objects skillfully.

People such as actors, dancers, swimmers, acrobats, athletes, jugglers, instrumentalists and artisans may exhibit developed bodily-kinesthetic intelligence.

Naturalistic Intelligence

The following definition is an abbreviation and adaptation by J. Keith Rogers and based upon his study of Howard Gardner's theory:

Naturalistic intelligence is the ability to understand, relate to, categorize, classify, comprehend, and explain the things encountered in the world of nature.

People such as farmers, ranchers, hunters, gardeners, and animal handlers may exhibit developed naturalistic intelligence

Ultimately in terms of testing, IQ measures the ability to do IQ tests, little theoretical footing exists to contradict this assertion. Tests in general rely heavily on vocabulary in order to transmit their information so already a bias is introduced in favour of those with superior vocabulary comprehension abilities. In this fashion another inaccuracy is introduced to IQ tests - they do not measure specific aspects of ones intelligence in isolation. Finally it must be asserted that generally we are more comforted by qualitative than qualitative aspects of intelligence. Consequently there persists the general assumption that in assigning numeric weight to questions we are actually testing intelligence.


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