Psychology- Intelligence Readings
Intelligence is not something that has concrete existence; it is, instead a socially constructed
Intelligence= the ability to acquire knowledge, to think and reason effectively and to deal
adaptively with the environment
Intelligence In Historical Perspective
Sir Frances Galton and Alfred Binet set the stage to measure intelligence and discover its causes
Sir Francis Galton: Quantifying Mental Ability
Strongly influenced by Darwins theory of evolution
Galton, in his book, showed through the study of family trees that eminence and genius seemed to
occur within certain families.
Galtons research convinced him that eminent people had inherited mental constitutions that
made them more fit for thinking than their less successful counterparts
Believed that the more social you were was biologically the reason you were more intelligent
Believed that the skull size reflected brain volume and hence intelligence
Alfred Binets Mental Tests
Binet was interested in solving a practical problem rather than supporting a theory.
Made 2 assumptions about intelligence:
o Mental abilities develop with age
o The rate at which people gain mental competence is a characteristic of the person and is
fairly constant over time- as a child grows whether at age 5 or 10, the child will always
be behind in intelligence
Binet created a test in which he asked teachers to come up with average questions, to separate the
slow kids from the average kids.
There would be a score in the end, a mental age
Mental age- the age at which the child is thinking. Example would be an 8-year-old thinking at a
10 year olds level. His mental age would be 10, but true age 8.
Practical implication was that educational attainment could be enhanced if placement in school
were based at least in part on the childs mental age
Intelligence quotient (IQ)- was the ratio of mental age to chronological age, multiplied by 100:
IQ= )mental age/ chronological age) X 100. A child who performed at his/ her level would have
an IQ of 100.
A child with mental age of 10 and chronological age of 8. IQ= (10/8) X 100= 125
Binets Legacy: An Intelligence Testing Industry Emerges
Lewis Terman, came up with a revised test to Binets called the Stanford- Binet. This test included
mostly verbal items, and it yielded a single IQ score
ARMY ALPHA- a verbally oriented test that was used to screen large numbers of US Army
recruits for intellectual fitness.
Because some recruits were unable to read, a non verbal instrument using mazes, picture
completion problems, and digit symbol tasks was also developed and given the name ARMY
David Wechler developed a major competitor to the Stanford Binet. Wechler believed that the
Stanford- Beneit relied too much on verbal skill. He thought intelligence should be measured as a
group of distinct but related verbal and non-verbal abilities.
Weschler tests are the most popular today.
The Nature Of Intelligence
Psychologists have used 2 approaches:
o The psychometric approach- attempts to map the structure of intellect and to discover the
kinds of mental capacities that underlie test performanceo Cognitive Process- approach studies the specific thought process that underlie those
The Psychometric Approach: The Structure Of Intellect
Psychometrics- the statistical study of psychological tests. Tries to identify and measure the
abilities that underlie individual differences in performance. It tries to provide measurement-
based map of the mind
To answer questions about intelligence, researchers administer diverse measures of mental
abilities and then correlate them with one another
If they correlate with one another highly (cluster mathematically) then performance= probably
reflects the same underlying mental skills. If the tests within a cluster correlate highly with one
another but much less with tests in other clusters then these various test clusters probably reflect
different mental abilities.
Factor analysis= reduces a large number of measures to a smaller number of clusters or factors
with each cluster containing variables that correlate highly with one another but less highly with
variables in other clusters. A factor allows us to infer the underlying characteristics that
presumably accounts for the links among the variables in the cluster.
a factor analysis tells us that there are 2 different factors.
It identifies the clusters for us
It is up to us to examine the nature of the tests within each cluster and decide what the underlying
factors might be.
The g Factor: Intelligence as General Mental Capacity
Charles Spearmen- observed that school grades in different subjects, were almost always
positively correlated, but not perfectly.
He found the same to be true with Beneits tests.
Spearmen concluded that intellectual performance is determined partly by a G FACTOR, or
general intelligence, and partly by wh