Psychology, Sixth Edition
- TESTING FOR INTELLIGENCE
Many psychologists agree with Robert Sternberg that three characteristics
encompass intelligence: possession of knowledge, ability to efficiently use knowledge to reason,
and ability to employ that reasoning adaptively in different environments.
- A Brief History of Intelligence Tests
Alfred Binet's original test included a series of age-graded items that demonstrated differences among children in reasoning, judgment, and problem-solving
abilities. Children who answered questions at their age level were considered
of "regular" intelligence. Louis Terman developed the Stanford-Binet test, devised a scoring method known as the intelligence quotient (IQ), and created the IQ test, which included questions for adults. Despite cultural biases, IQ tests
were given to screen immigrants and to place soldiers in appropriate assignments.
David Wechsler developed a new test that was made up of several subtests. Wechsler's test reduced the extent to which answers depended on a certain culture
and had some subtests that had little or no verbal content.
- Intelligence Tests Today
The Wechsler test, which is designed to be administered individually, includes the
verbal scale and the performance scale.
The average result obtained by people at each age level is assigned an intelligence quotient, or IQ score, of 100. Each individual's score is compared to the average for his or her age level in order to compute an
IQ. Therefore, an IQ score is a relative measurement.
- Aptitude and Achievement Tests
These two types of tests are closely related to intelligence tests. Aptitude tests are designed to gauge a person's ability to learn or do certain things. Achievement tests measure how much a person already knows in a certain area.
- MEASURING THE QUALITY OF TESTS
Tests have two advantages over other means of evaluation: they are standardized
so that different people's performances can be compared, and they are quantifiable (which allows the
calculation of norms).
If a test has reliability, a person will receive about the same score when tested on different occasions.
There are three methods of checking the reliability of a test: test-retest,
alternate-form, and split-half reliability. If the correlation coefficient between two scores is high and positive, the
test is considered reliable.
A test that has validity measures what it is designed to measure. There are several measures of validity, including content validity, criterion validity, and predictive
- EVALUATING IQ TESTS
- The Reliability and Validity of IQ Tests
How Reliable Are IQ Tests? IQ tests usually provide consistent results. However, test-retest reliability
can be low if the initial testing is done prior to seven years of age. The
testing conditions and the person's motivation when taking the test can also affect results.
How Valid Are IQ Tests? The validity of IQ tests is difficult to measure, in part because intelligence
itself is difficult to define. IQ tests do a reasonably good job of predicting academic and job success, but scores can
be distorted by the response to the tester.
How Fair Are IQ Tests? Controversy about the fairness of IQ tests continues, especially in terms of cultural factors. Although many of the technical problems in IQ tests have
been solved, the social consequences of testing should be evaluated.
- Thinking Critically: Are IQ Tests Unfairly Biased Against Certain Groups?
What am I being asking to believe or accept?
Intelligence tests are biased against some minority groups.
What evidence is available to support the assertion?
Differences in IQ scores may reflect motivation and a person's trust in the test administrator. Some tests are not "culture fair." People may interpret the test questions intelligently but differently than
the defined "right" answer.
Are there alternative ways of interpreting the evidence?
Intelligence tests may be biased in assessing general intelligence, but they
may still be good predictors of who will do well in school or on the job.
What conclusions are most reasonable?
Current tests, while not completely culture fair, can be useful as predictors of success
in the culture in which they are administered. Psychologists should also
spend time developing alternative tests based on problem-solving skills and
more open-ended questions.
- IQ Scores as a Measure of Innate Ability
The influences of heredity and the environment interact to produce intelligence.
Correlational studies with twins suggest that heredity influences the development
of IQ. However, the environment also exerts a strong influence on IQ. Previously
underprivileged children placed in homes that provide an enriching intellectual
environment have shown moderate but consistent increases in IQ. And children
placed in enrichment programs show improved health, academic achievements, and intellectual skills.
- Group Differences in IQ Scores
An examination of the differences among group means on IQ tests does not
provide information about specific individuals in those groups. A person in the low score group may
have an individual score that is much higher than a person from the high
score group. In addition, inherited features may be influenced by the environment.
Socioeconomic Differences. A child's ability is influenced by genetic factors and perhaps by the effects of
the parents' occupation and education on the home environment. Also, higher-income families
may encourage a higher level of motivation to succeed.
Ethnic Differences. There is variation in average IQ scores between ethnic groups, but more
variation within groups. Research indicates that differences in IQ among
ethnic groups may be due to differences in socioeconomic environment, parental education, nutrition, health
care, and schools. Also, people in some cultures may be more or less motivated
during testing, depending on the value their cultures place on education
- Conditions That Can Raise IQ Scores
Enrichment programs such as Head Start can cause at least temporary gains
in IQ scores. Spending time in projects such as Head Start may cause a child
to be more motivated and have a better attitude toward school.
- IQ Scores in the Classroom
IQ scores may influence teachers' expectations about the abilities of their students. In turn, these expectancies
may influence students' performance. But IQ scores can also help educators identify student strengths and weaknesses
and offer a curriculum that will best serve the students.
- Linkages: Emotionality and the Measurement of Cognitive Abilities
People tend to perform at their best when their arousal level is moderate.
Too much or too little arousal will result in decreased performance. Those
whose arousal inhibits their performance in testing are said to suffer from
text anxiety. Concern over negative stereotypes about the mental abilities of the group to which they belong
can impair test performance of some members of ethnic minorities. In sum,
people who are severely anxious about testing will not perform to the best
of their ability.
- UNDERSTANDING INTELLIGENCE
- The Psychometric Approach
The psychometric approach tries to describe the structure of intelligence by examining the correlations among scores on various tests. Charles Spearman postulated two types
of intelligence that account for test scores: general intelligence or g; and special intelligences, or s, which are the specific skills and knowledge needed to answer the questions on a particular test. L. L. Thurstone disagreed. He used factor analysis, a
statistical technique, to find several independent primary mental abilities,
including numerical ability, reasoning, verbal fluency, spatial visualization,
perceptual ability, memory, and verbal comprehension. Later, Raymond B. Cattell argued that g exists
and that it consists of fluid intelligence and crystallized intelligence. Most psychologists agree that there is g. They just do not agree on what g is.
- The Information-Processing Approach
Psychologists using the information-processing approach have tried to understand intelligence by examining the mental processes
involved in intelligent behavior. Research suggests that those with greater intellectual ability have more attentional
resources available when performing a task. Speed of basic processing plays
only a small role in determining intelligent behavior.
- The Triarchic Theory of Intelligence
Robert Sternberg proposed the triarchic theory of intelligence: analytic, creative, and practical. In this view, intelligence is composed
of internal components, the relation of components to the external world,
and adaptation to the environment. The internal components are performance components,
knowledge-acquisition components, and metacomponents. The first two components
are the information-processing capacities of perceiving stimuli, holding
information in working (short-term) memory, performing transformations on that information, and retrieving
information from memory. Metacomponents are the processes involved in organizing
and setting up a problem. The relationship between components and the external
world is the ability to profit from experience. Adaptation to the environment can be thought
of as "street smarts."
- Multiple Intelligences
In his theory of multiple intelligences, Howard Gardner proposed that certain abilities are relatively independent of one another and that individuals may develop
some "intelligences" more highly than others. Gardner suggested eight different intelligences:
linguistic, logical-mathematical, spatial, musical, body-kinesthetic, intrapersonal (self-knowledge), interpersonal (social skills), and naturalistic.
- Focus on Research Methods: Tracking Cognitive Abilities over the Life Span
Age-related changes in mental abilities can be examined through cross-sectional and longitudinal studies. The cross-sequential with resampling
design combines cross-sectional and longitudinal studies. Results show that
crystallized intelligence may continue to grow into old age. Fluid intelligence
remains stable in adulthood and then declines in late life. Specifically, problems in working
memory, processing speed, problem-solving strategy organization, flexibility,
and control of attention appear late in life.
- DIVERSITY IN COGNITIVE ABILITIES
Creativity is often assessed by tests of divergent thinking, which measure the ability to generate many different but plausible responses
to a problem. Expertise in the field, a set of creative skills, and intrinsic motivation are necessary
for creativity. External rewards can deter creativity. The correlation between
IQ scores and creativity is not very high. IQ tests measure convergent thinking, whereas creativity is characterized by divergent thinking.
- Unusual Cognitive Ability
Giftedness. Those with extremely high IQs do not necessarily become creative geniuses. They do, however, usually become very successful in this society or culture.
Mental Retardation. This label is applied to people whose IQs are 70 or below and who fail
at daily living skills. Mental retardation sometimes has very specific causes, such as Down syndrome. In most cases of familial
retardation, there is no specific cause. Psychologists believe familial retardation
results from an interaction between heredity and the environment. Children
with mild retardation differ from other children in three ways: they perform certain mental
operations more slowly, they know fewer facts about the world, and they are
not very good at using particular mental strategies in learning and problem
solving. In general, children with mental retardation are deficient in metacognition.
Learning Disabilities. People with learning disabilities have academic performance that doesn't measure up to their measured intelligence. People with dyslexia see letters as distorted or jumbled. Dysphasia is difficulty in understanding spoken
words. In dysgraphia a person has trouble writing, while in dyscalculia a
person has trouble with arithmetic.