Define intelligence
the ability to use one’s mind to solve novel problems and learn from experience
What did Henry Goddard contribute to the area of intelligence testing?
- Administered intelligence tests to European immigrants arriving in America
- Concluded that the majority of Jews, Hungarians, Italians, and Russians were “feebleminded”
- Also used his tests to identify feebleminded American families, whom he claimed were responsible for the nation’s social problems
- Advocated for their segregation and sterilization (American governments subsequently restricted immigration from south/eastern Europe and passed laws requiring sterilization of “mental defectives”
What were intelligence tests originally developed for?
To help underprivileged children succeed in school
What did Alfred Binet contribute to the area of intelligence testing?
- Psychologist in France during the end of the 19th century, when public schools were being developed
- Believed that schools should use objective methods to determine the learning capabilities of a child, rather than subjective reports from parents/psychiatrists/teachers
- Children who needed extra help should be placed in special classrooms with peers, not in asylums
- Tests were designed to measure aptitude for learning, independent of the child’s prior educational achievement; averages were used to determine the “mental level” (age) of a child
What did William Stern contribute to the area of intelligence testing?
- German psychologist in the early 20th century
- Suggested that a child’s “mental level” could be thought of as a “mental age” and used to determine whether they were developing normally
- Ratio and deviation IQ
What is the difference between ratio and deviation IQ? What is the issue with ratio IQ?
ratio IQ: a statistic obtained by dividing a person’s mental age by the person’s physical age and then multiplying the quotient by 100
○ Issue: intelligence increases dramatically in the first decade of life and then levels off, skewing results for adults especially
deviation IQ began to be used: a statistic obtained by dividing a person’s test score by the average test score for people of that age and then multiplying the quotient by 100
○ When we talk about IQ scores today, we are almost always talking about deviation IQ
What are the most widely used modern intelligence tests?
Those which have their roots in the test developed by Binet and Simon:
• Stanford-Binet Intelligence Scale (based Binet and Simon’s original version, update by Lewis Terman of Standford University)
• Wechsler Adult Intelligence Scale (WAIS) and Wechsler Intelligence Scale for Children (WISC) (most widely used modern tests; developed by David Wechsler, a WWI US Army psychologist)
• These tests use various tasks to determine intelligence, and none involve the writing of words
Which life outcomes can be predicted by performance on intelligence tests?
- Income (intelligent people are more likely to be patient, better at calculating risk, predicting how other people will react, etc.; more likely to get more education)
- Amount of education received (a better predictor than even social class; people with high IQs spend more time in school and perform better while there)
- Health and longevity (less likely to smoke or drink, more likely to exercise and eat well
- Relationships
What is the two-factor theory of intelligence? Who is credited with developing it?
a person’s performance on a test is due to a combination of general ability (g) and skills that are specific to the test (s)
Charles Spearman
What did Louis Thurstone conclude about the two-factor theory of intelligence?
- There is actually no such thing as general ability
- Instead, there are a few stable and independent mental abilities
What are Thurstone’s Primary Mental Abilities?
- Word fluency
- Verbal comprehension
- Numerical ability
- Spatial visualization
- Associative memory
- Perceptual speed
- Reasoning
What is confirmatiory factor analysis?
a new mathematical technique of the 1980s which revealed that correlations between scores on different tests are best described by a three-level hierarchy, with a general factor (similar to Spearman’s g)at the top, specific factors (similar to Spearman’s) at the bottom, and group factors (similar to Thurstone’s primary mental abilities) in the middle
• Suggests that people have a very general ability called intelligence, which is made up of a small set of middle-level abilities, which are made up of a large set of specific abilities unique to particular tasks
What is the data-based approach, when it comes to middle-level cognitive abilities?
computing the correlations between people’s performances on a large number of tests and then seeing how those correlations cluster
• Some people are really good at the specific tasks of fly swatting and teacup balancing because they have a middle-level ability called physical coordination, but this middle-level ability is unrelated to the other middle-level ability, academic skill, which is why these people are not necessarily good at summing numbers or understanding Shakespeare.
• Examining the pattern of correlations between different tests reveals the nature and number of the middle-level abilities.
What are Carroll’s 8 middle-level abilities?
- Memory and learning
- Visual percetion
- Auditory perception
- Retrieval ability
- Cognitive speediness
- Processing speed
- Crystallized intelligence
- Fluid intelligence
What is crystallized intelligence?
the ability to apply knowledge that was acquired through experience; generally measured with tests of vocabulary and factual information
What is fluid intelligence?
the ability to solve and reason about novel problems; generally measured with tests that present abstract problems in new domains that must be solved under time pressure
What is the theory-based approach when it comes to middle-level cognitive abilities? Who is it associated with?
because standard intelligence tests present clearly defined problems that have one right answer, and then supply all the information needed to solve them, they can measure only analytic intelligence; in everyday life, people find themselves in situations in which they must formulate the problem, find the information needed to solve it, and then choose among multiple right answers (these situations require creative and practical intelligence)
Robert Sternberg
What additional middle-level cognitive abilities did Sternberg identify?
- Analytic intelligence: the ability to identify and define problems and to find strategies for solving them.
- Creative intelligence: the ability to generate solutions that other people do not
- Practical intelligence: the ability to implement these solutions in everyday settings
What is emotional intelligence?
the ability to reason about emotions and to use emotions to enhance reasoning; one of the middle level abilities that the data-based approach missed; emotionally intelligent people…
• Know what kinds of emotions a particular event will trigger
• Can identify, describe, and manage their emotions
• Know how to use their emotions to improve their decisions
• Can identify other people’s emotions from facial expressions and tones of voice
• Show less neural activity when solving emotional problems
• Have better social skills and tend to be happier
What is the heritability coefficient (h2) when it comes to intelligence?
a statistic that describes the proportion of the difference between people’s IQ scores that can be explained by differences in their genes
• Roughly 50% to 70% of the difference between people’s intelligence test scores is due to genetic differences
What are some common misunderstandings of the heritability coefficient?
- The heritability coefficient is not the same as the correlation coefficient
- “the heritability of intelligence is roughly .5” does not mean half of your own intelligence is due to your genes and the other half to experiences; the heritability coefficient measures differences between people, not how much of a particular person’s intelligence comes from which source
What is the difference between shared and non-shared environment?
Shared environment: features of the environment that are experience by all relevant members of a household (ex. nutrition, access to books, etc.)
Nonshared environment: features of the environment that are not experience by all relevant members of a household (ex. friends, teachers, illnesses, etc.)
The closer siblings are in age, the higher the correlation between their IQs; they are more likely to have the same teacher, contract the same illnesses at the same time, etc.
What factors can influence heritability coefficients?
- Intelligence is not equally heritable among high- and low-income children in America, but is equally heritable among high- and low-income children in more socioeconomically equitable places like Western Europe and Australia (both high- and low-income citizens have more equal amounts of nutrition and leisure, more equal access to books, etc.); environment plays a role
- The heritability of intelligence is higher among adults than among children; the environments of older people are more similar than the environments of younger people, and when environments don’t differ much across people, then differences in their intelligence scores must be due to the one thing that does differ: their genes.
What is the Flynn effect?
the average IQ score today is roughly 30 points higher than a century ago; why?
- Better nutrition, schooling, parenting, etc.
- Less intelligent people not having children
- Industrial and technological revolutions have changed the nature of daily living in such a way that people now spend more time solving the kinds of abstract problems included on intelligence tests
