A Working Definition Of Intelligence
Intelligence is the ability to direct one's thinking, adapt to one's circumstances, and learn from one's
experiences. In other words, intelligence is the ability to use one's mind to solve novel problems and
grow from that experience. From an evolutionary biology point of view, it is better to think of
intelligence as an ecological niche, like the skin of a chameleon.
Why is a creating a simple 'working definition' of intelligence so difficult? One of the reasons is
anthropocentrism, the projection of human abilities onto non-human organisms. If they don't have
human qualities, such as auditory language, we don't perceive them as intelligent. So what do we make
of brainy bees? https://www.pnas.org/doi/abs/10.1073/pnas.1202576109
Intelligence is a process (or a set of processes) not a thing. There is a common mistake called
reification, or making intelligence a single object. During this chapter, reification will play itself out as
the argument over the existence of a general or 'g' factor of intelligence.
Measuring Intelligence
How do we measure intelligence? The worst misuse of measurement occurred in the 1920s on Ellis
Island, when Henry Goddard administered intelligence tests to Jews, Hungarians, Italians, and
Russians. He concluded that they were 'feeble-minded' That's because the test was in collegiate
English. The U.S. subsequently passed laws restricting the immigration of people from Southern and
Eastern Europe, and 27 states passed laws requiring the sterilization of 'mental defectives'.
Canada is not exempt from this kind of misuse of science. Sterilization laws for mental defectives were
passed in British Columbia and Alberta in the 1920's and not taken off the books until 1972.
Intelligence tests were originally developed when France made primary school education available to
every class, and suddenly French classrooms were filled with children who differed dramatically in
their ability to learn. Poor children had come with their parents from the French countryside, looking
for jobs in factories, and they moved into the suburbs of Paris (which are still filled with poor
immigrants.) Binet developed tests for an intelligence quotient, or I.Q.
Binet's goal was to measure what he termed natural intelligence, and his tests did this by creating a
test environment by disregarding the degree of instruction the subject already possessed. The subject
was given nothing to read, nothing to write, and submit the subject to no test by which he might
succeed through rote learning. In short, Binet was measuring aptitude as contrasted to prior
educational achievement. Stern, (1914) quantified Binet's approach and created the Ratio I.Q, which
is a statistic obtained by dividing a person's mental age by the person's physical age and then
multiplying the quotient by 100. Used for testing children. Updating the test for adults the Deviation
I.Q. is a statistic obtained by dividing a person's test score by the average test score of
people in the same age group and then multiplying the quotient by 100. Used for testing adults.
Modern Intelligence Testing: The WAIS
Wechsler Adult Intelligence Scale or WAIS consists of a set of sub-tests for verbal comprehension,
perceptual reasoning, working memory and processing speed.
For more go to: https://strategicpsychology.com.au/wais/
For the next exam, study Table 10.1
To see how well you can understand the WAIS: answer this set of questions:
(1) What are the core subtests for Verbal Comprehension? Give one test example;
(2) What are the core subtests for Perceptual Reasoning? Give one test example.
(3) What are the core subtests for Working Memory? Give one test example.
(4) What are the core subtests for Processing Speed? Give one test example.
That last one is particularly interesting in terms of neuroscience, because research has shown that
individuals with greater cognitive abilities display a greater speed of higher-order cognitive processing.
https://link.springer.com/article/10.1007/s42113-018-0021-5
In conclusion, the WAIS is the most widely used intelligence test, and high predictive validity for
important life outcomes, such as income. One reason for this is that intelligent people have a variety of
traits the promote economic success: they more patient; better at calculating risk; better at predicting
how other people will act and how they should respond. The main reason, however, is that they get
more education (or in the age of the internet, are they simply more educable?). (Deary et al., 2005) A
person's I.Q. is a better predictor of the amount of education they will receive than their social class.
(Deary, 2012).
Equality in Smartland
Nikolaev and Salahodjaev (2016) gathered data on intelligence and happiness from citizens in 21
countries. They found a positive correlation between a nation's average IQ and its average happiness.
Calculating happiness using the statistical standard deviation (or 'spread' of scores around an average
value) they coined the term 'happiness equality'. If two nations have the same average happiness, the
smarter nation tends to distribute that happiness more equally among its citizens. To sum up, if many
citizens are ecstatically happy, and many are despondent, then the standard deviation is high, and
happiness equality is low.
Intelligence Quotient Versus Academic Performance
The correlation between I.Q. and academic performance is roughly 0.5 9 (or modest) across a wide
range of people and situations. Schmidt & Hunter (1998) conclude that for hiring employees without
previous experience in the job, the most valid measure of future performance and learning is general
mental ability. This last term 'g factor' will be discussed in more depth, as it is highly contested.
The ability to delay gratification is also a powerful predictor of life success (Duckworth & Seligman,
2005) but is an aspect of emotional intelligence, which is arguably not the same as 'g factor'.
Are there other reliable measures of intelligence? Yes. Murphy et al., (2003) reported that intelligence
people hold the gaze of their conversation partners both when they are speaking and when they are
listening, especially so if the judges are women.
What Is Intelligence?
Charles Spearman developed a statistical technique called factor analysis which explains a large
number of correlations in terms of a small number of underlying factors. Schacter's text uses the same
approach that I do, to understand this technique by defining athleticism as an underlying factor in
hockey and softball. Spearman argued that there is a single, general ability called intelligence that
enables people to perform a variety of intelligent behaviours. Remember what I said about reification
here. For Spearman, if intelligence is a single, general ability there should bea very strong correlation
between people's performance on all kinds of tasks.
Spearman had to modify his theory to explain why a child who scored the highest in math did not score
the highest in spelling (but still did well). He posited a two-factor theory of intelligence: every task
requires a combination of general ability and skills specific to the task.
Louis Thurstone disagreed. Scores on verbal tests might be highly correlated, but comparing scores on
perceptual tests to verbal tests indicated a lesser degree of correlation. This 'clustering of correlations'
indicated for him that 'g' did not exist. He posited three primary mental abilities: perceptual, verbal,
and numerical. Those three could be operationalized in six areas: word fluency, verbal comprehension,
numeric ability, spatial visualization, associative memory, perceptual speed, and reasoning.
A new statistical technique--confirmatory factor analysis--was verified by Carroll in 1993, using a reanalysis of massive amounts of data from more than 130, 000 healthy adults, school children, infants,
college students, people with learning disabilities, mental and physical illnesses demonstrates a threelevel hierarchy. Most intelligence test data are best described with general intelligence at the top;
specific abilities at the bottom, and a small number of mid-level abilities in the middle.
Applications of Fig. 10.2 will be on the next exam.
Data-based approach
This starts with people's responses on intelligence tests, then looking to see what kind of independent
clusters these responses form. Others use a theory-based approach starting with a broad survey of
abilities, looking to see which abilities a particular intelligence test measures. For the data-based
approach, patterns of correlations can reveal middle-level abilities. For example, four specific abilities:
(a) balancing teacups, (b)swatting flies,(c) understanding Shakespeare, and (d) summing numbers can
be thought of as instances of physical coordination (a+b) and academic skill (c+d).
Carroll (1993) concluded that there are eight independent middle level abilities: memory & learning;
visual perception; auditory perception; retrieval ability; cognitive speed; processing speed; crystallized
intelligence; and fluid intelligence. Fluid intelligence is the ability to see abstract relationships and
draw logical inferences; crystallized intelligence is the ability to retain and use knowledge that was
acquired through experience.
Raven's Progressive Matrices Test
Your exams test crystallized intelligence; fluid intelligence tests pose novel, abstract problems that are
solved under time pressure, such as Raven's Progressive Matrices Test. This type of test is less likely
to be culturally biased.
See for yourself: https://classicaliqtest.com/raven-test/
Raven’s Progressive Matrices is a classical non-verbal test used to measure abstract reasoning and
fluid intelligence. The test has been developed by John C. Raven since 1936. It consists of 60 visual
questions created by logical matrices, the users shall choose the correct answer in 6 or 8 available
multiple-choice questions. The questions are made in sequences from easy to difficult to identify the
different parts of your liquid (fluid) intelligence.
This is a completely non-linguistic test so it is fair across cultures and thus becomes the world’s most
famous and popular test. Over the 86 years since its publication, Raven’s Progressive Matrices has been
widely used by psychologists and the test has been accepted as a standard to join some famous
organizations such as The Triple Nine Society, The International Society for Philosophical Enquiry,…
The test has clinical and neurological evaluation, educational placement, occupational assessment,
adult neurology treatment and aptitude research.This test has been used and trusted by professional
psychologists for near 100 years in 151 countries, in particular the United States.
Sternberg's Multiple Intelligences
Sternberg posited that there are three kinds of intelligence, only one of which is measured by standard
intelligence tests. His are: analytical intelligence; practical intelligence, and creative intelligence.
Sternberg argued that tests of practical intelligence are actually better than tests of analytical
intelligence at predicting a person's job performance. Finally there is emotional intelligence,
discussed in depth in Web Article Two. Here we find alexthymia, difficulty in identifying and
describing one's own emotions.
Emotional Intelligence
John Mayer and Peter Salovey define emotional intelligence as the ability to reason about emotions and
to use emotions to enhance reasoning. Areas of focus for emotional intelligence are: knowing 'trigger
conditions' for various emotions; identifying, describing and managing emotions; using emotions to
improve decision-making; identifying the emotions of others from facial expressions and tones of
voice. Emotionally intelligence people use less neural activity when solving emotional problems than
do the less emotionally intelligent.
Genetic Influences on Intelligence
Identical twins (monozygotic) versus fraternal (dizygotic) twins allow us to estimate the influence
genes have on intelligence. I.Q. of identical twins raised in the same household have a correlation of
+0.86 (very high). Identical twins separated at birth have +0.78 (still very high). Identical twins raised
apart have more similar I.Q.s than fraternal twins raised together. Bouchard & McGue, (2003) report
that unrelated people raised in the same household (one adopted) have a modest +0.26. Genes define
intelligence.
Heritability coefficient describes the proportion of the difference among people in a given population
that can be explained by differences in their genes. Much research (eg: Chabris et al., 2012) concludes
that 50% in the difference in people's intelligence test scores (within a particular group) is due to
genetic differences. Note that this statistic only applies to groups, not individuals. Think tribes.
The heritability coefficient of intelligence among wealthy children is .72, and for poor children .10.
(Turkheimer et al., 2003) Why? Poverty may create much more random home environments.The value
of the heritability coefficient also depends on the age of the people being measured and is typically
larger among adults than among children. When people have identical experiences, the difference in
their intelligence must be due to the difference in their genes. This is shared environment, those
environmental factors that are experienced by all relevant members of a household. Don't forget that
the most important shared environment is the womb; that is the importance of twin studies.
Absolute intelligence changes over time. For most people intelligence increased between adolescence
and middle age and thereafter begins to decline. The sharpest decline occurs in old age, and may be
due to a general slowing of the brain's processing speed. (Zimprich & Martin, 2002). Vocabulary
decreases the least (crystallized intelligence), abstract material (fluid intelligence) decreases the most.
Ramsden et al. 2011 studied variation of IQ over time in a group of British teenagers, ages 12-20. The
researchers used standardized tests of measure IQ twice, about 3 years apart, and they found that
teenager's scores were surprisingly variable. Brain structure changed between Time 1 and Time 2 tests
in ways that related systematically to changes in IQ. For example, changes in gray matter volume in a
region of the left frontal lobe were important for speech production, which is correlated with their
verbal subscale score. The implication is that even in adolescence, local brain regions are growing or
shrinking over time.
Flynn effect (2012) The actual I.Q. score is 30 points higher than it was a century ago. Flynn posited
that technological revolutions have given people more time to solve the kind of abstract problems that
intelligence tests include. So, no sense complaining about smartphones and videogame, which are
everywhere on the planet. Every time some in Somalia texts a message, their literacy improves.
Individual Difference in Intelligence
If the average I.Q. is 100 and the vast majority of us--68% to be exact--have an I.Q. between 85 and
115, we see a normal curve being generated. Every 15 points below that is intellectually disabled,
every 15 points above is intellectually gifted. Myths abound, here is the truth: People with very high
intelligences are less prone to mental illnesses.(Didden et al., 2012). Indeed a 15 point decrease in I.Q.
at age 20 is associated with a 50% increase risk for hospitalization due to schizophrenia, mood
disorder, and alcohol related disorders .(Gale et al.,2010).However, 95% of gifted children show a
sharp disparity between their mathematical and verbal abilities. (Achter, Lubinski & Benbow, 1996). If
gifted children seem odd, it may because of their 'rage to master', they spend more time than their less
gifted peers in the sheer amount of time they spend in their domain of giftedness. (Ericsson &
Charness, 1999).
About 70% of people with I.Q.s below 20 (profound) are male.
Between I.Q. 50 and 35 Two of the common causes are Down's syndrome (caused by the presence of a
third copy of chromosome 21). and FASD.
Down syndrome (sometimes called Down's syndrome) is a condition in which a child is born with an
extra copy of their 21st chromosome — hence its other name, trisomy 21. This causes physical and
mental developmental delays and disabilities.