Psychology Chapter 10 Notes (Intelligence)
Intelligence is the ability to acquire knowledge, think and reason effectively and deal adaptively
with the environment
o A host of abilities encompass intelligence
Intelligence in the Historical Perspective
Sir Francis Galton’s research led him to determine that intelligence was inherited; that eminent
people inherited ‘mental constitutions’ that made them more fit for thinking than poorer people
o Galton also believe that intelligence was directed tied to an individual’s ability to their
speed of their nervous system (unitary intelligence)
o As well, he measured skull size, thinking that skull size was proportional to brain volume
and therefore, intelligence.
o Later, Galton’s theories fell into disfavour due to the fact that nervous system efficiency
were proved to be unrelated to relevant mental ability, such as academic and
A psychologist named Spearman decided that intelligence needed better statistics; he looked for
patterns of correlation which gives individuals a ‘g’ factor.
o All the tests must be correlated for this to work, however.
In the 20 century, Alfred Binet was commissioned by the French Ministry of Public Education to
create a test.
o Binet made 2 assumptions while creating that test:
That mental ability develops with age
The rate at which people gain mental competence is a characteristic of the
person and is constant over time
o Binet personally believed that intelligence was a collection of higher-order abilities, but
there was correlation of his belief; he believe that intelligence was multiplex
o Using answers asked from teachers, Binet created a test where an examiner would ask a
child to solve questions suitable for his/her age.
Results from the testing would indicate the child’s mental age.
The concept of mental age was adapted by William Stern, a German
psychologist who created the IQ by using
o While this was able to be used on children, the Stern’s quotient
does not apply on adults
Lewis Terman, a professor at Stanford, was intrigued by Binet’s work. He revised the test and it
became known as the Stanford-Binet.
o The test included certain things that inidividuals of a certain age must be able to
2-2 ½ year olds must be able to insert blocks into appropriate holes into
6 year olds must be able to define words such as envelope o During World War 1, a student of Terman’s adapted the test to the screening of Army
individuals called Army Alpha.
o A non-verbal version, called Army Beta, was created.
David Weschler developed a test in 1939 called the Weschler Adult Intelligence Scale (WAIS),
followed by a test for children called the Weschler Intelligence Scale for Children (WISC) in 1955.
o The WAIS-III and WISC-IV are the most popular tests in North America
The WAIS has 10 subscales with both verbal and performance based measures.
It uses a deviation based IQ scale
Mean IQ is 100, standard deviation is +/- 15
Another psychologist named Thurstone believed that intelligence was based off of primary
mental abilities (he belived 7 accoutned for intelligence)
o His tests require no g factor and showed better statistics than those of Spearman’s.
However, there are no correlation at all between the tests.
There are other models of intelligence, such as Cattel’s (based off of fluid and crystalized
intelligence), Gardner’s (multiple intelligences) and Sternberg’s (triarchic theory)
The Measure of Intelligence
One question that developers still ask is that should you test for the aptitude for learning or test
what a person already knows?
o An achievement test is designed to test how much an individual already knows
o An aptitude test is designed to test how much an individual is capable of learning
A psychological test is a method for measuring individual differences related to some
psychological concept or construct based on a sample of relevant behaviour in a scientifically
designed and controlled environment.
o Reliability refers to the consistency of measurement
A test-retest reliability is whether two test scores, taken at separate times from
each other, are about the same
Internal consistency is the measure of consistency concerning the measurement
of the test itself.
Interjudge reliability refers to the