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Please be aware that this is a student-generated wiki designed for review for my students' AP exams. Come in, look around, and enjoy yourself...just be aware of the nature of this wiki. Even though most everything is correct, I advise caution before citing this as an authoritative source.


Origins of Intelligence Testing
  • Intelligence Test
  • the two standardized IQ test are Stanford-Binet (most commonly used) and Wechsler
  • a method of assessing an individual's mental aptitudes and comparing them to those of others, using numerical scores (Myers)
    • The modern intelligence-testing movement began when the pioneering French psychologist Alfred Binet developed a test to predict children's future school performance. Binet's test was designed to compute a mental age for each child (Myers).
    • Today's intelligence tests no longer compute an intelligence quotient; instead they produce a mental ability score based on the test-taker's performance relative to the average performance of others the same age. (Myers 421)
    • ex: Should a 40-year-old who does well on the test as an average 20-year-old be assigned an IQof only 50? (Myers 421)
    • a measure of intelligence test performance devised by Binet; the chronological age that most typically corresponds to a given level of performance. Thus a child who does as well as the average 8-year-old is said to have a mental age of 8. (Myers 420)
    • to measure mental age, Binet and Simon theorized that mental aptitude, like athletic aptitude is a general capacity that shows up in various ways. Through reasoning and problem solving questions they were able to predict how well children handle school work (Myers).
    • This method is not very common today because there are questions as to its accuracy
    • Binet and Simon assumed that all children follow the same course of intellectual development but that some develop more rapidly. (Myers 420)
    • Binet and Simon refused to speculate about what the test was actually measuring, but he insisted that it did not measure inborn intelligence (Myers 420).
  • Stanford-Binet
    • the widely-used American revision of Binet's original intelligence test
    • revised by Terman at Stanford University
    • Terrman revised the test by adapting some of Binet;s original items, added others, established new age norms, and extended the upper end of the test's range from teenagers to "superior adults." (Meyers 421)
    • Terman promoted the widespread use of intelligence tests to "take account of the inequalities of children in original endowment by assessing their "vocational fitness". (Myers, 420)
    • In 1924, Terman's revised version was used to evaluate WWI army recruits. (Myers, 421)
    • Intelligence Quotient (IQ)- defined originally the ratio of mental age (ma) to chronological age (ca) times (X) 100.
    • The IQ was derived by German psychologist William Stern, using tests like the Stanford-Binet (Myers).
    • works better for children
    • The term is no longer used; it is now referred to as "intelligence test score" (Myers).
    • Most current intelligence tests, including Stanford-Binet, no longer compute an IQ. (Meyers 421)
    • Today's intelligence tests produce a mental ability score based on the test-taker's performance relative to the average performance of others the same age. (Meyers 421)
    • IQ = mental age/chronological age x 100
    • the average IQ score is 100, with about two-third of all people scoring between 85 and 115 (Meyers 421). This is because the distribution of IQ scores is roughly normal with a standard deviation of 15 points.
    • Ex: A 8 year old child has the mental age of a 10 year old. 10/8 x 100 = an IQ of 125
    • With Terman's help, the U.S. government developed new tests to evaluate newly arriving immigrants and 1.7 million World War I army recruits, effectively making it the world's first mass administration of an intelligence test (Meyers 421)
    • Among the most controversial issues in psychology is the debate over intelligence testing
    • Can tests measure and quantify a person's abilities?
    • How widely can the results be used fairly?

What is Intelligence?
The ability to learn from experience, solve problems, and use knowledge to adapt to new situations. (Myers)
Referring to someone's IQ as a fixed and objectively real trait is a reasoning error called reification- which views an abstract, immaterial concept as a concrete thing (Myers).
Intelligence is said by psychologists to be not something concrete but a concept. (Myers)
Psychologists debate whether we should define it as an inherent mental capacity, an achieved level of intellectual performance, or an ascribed quality that, like, "beaut is in the eye of the beholder". (Myers)
Intelligence can be defined as goal-directed adaptive thinking (The Princeton Review).
Intelligence is a social constructed concept. Culture deem "Intelligence" whatever attributes enable success in those cultures. (Myers)
  • When we referred to someone's "IQ" (intelligence quotient) as if it were a fixed and objectively real trait like heigh or weight we commit a reasoning error called reification (viewing an abstract, immaterial concept as if it were a concrete thing) To reify, is to invent a concept, give it a name, and then convince ourselves that such a thing objectively exists in the world. When someone says, "she has an IQ of 120," they are reifying IQ; they are imagining IQ to be a thing one has, rather than the score once obtained on a particular test. One should say, "her score on the intelligence test was 120" (Myers 422)
  • According to Myers, in rural Kenya, intelligence would be the ability to identify which herbal plants that can be used to treat certain diseases. In western cultures, intelligence would be based on cognitive tasks such as strategy use and reasoning, or analyzing skills
Intelligence has a few controversies that remain still:
  1. Is Intelligence one general ability or several specific abilities?
  2. Can we locate and measure intelligence within the brain?
  3. Is intelligence hereditary?
  4. Is an IQ test the only way to determine the intelligence of someone?
  • Factor Analysis- helps researchers to find clusters of test items that will measure a common ability. It is a statistical procedure that identifies clusters of related items (called factors) on a test; used to identify different dimensions of performance that underlie one's total score (Myers 423).
    • It is used to identify different dimensions of performance that underlie one's total score
    • The primary assumption that the Factor Analysis theory makes is that all tasks are separate and do not influence each other. Researchers have pointed out that this is not always the case as a good reader can be a good writer merely because he/she has been revealed to so much good writing.
    • for example, grouping algebra (cluster 1) and geometry (cluster 2) under math (common ability).
    • example: people who do well on vocabulary items often do well on paragraph comprehension. (Myers)
    • example~ you can be taking a math test and have different types of questions. like algebra, pre-cal, and calculus.
    • there is a chance for a person to be advanced in more than one aspect such as verbal intelligence and spatial ability. (Myers)
    • Spearman believed that the g factor, underlies all of our external image arrow-10x10.png behavior, from navigating the sea to excelling in school. (Myers)
  • General Intelligence (g)- A general intelligence factor that Spearman and others believed underlies specific mental abilities and is therefore measured by every task on an intelligence test.
    • general mental capacity expressed by a single intelligence score was contraversial in spearmens day and remains in our own.(Myers)
    • we might then liken mental abilities to physical abilities; Athleticism is not one thing but many(Myers)
    • "One of Spear man's early opponents was L. L. Thurstone. He gave 56 different tests to people and mathematically identified a clusters of 'primary mental abilities', such as word fluency, memory, and reasoning. Thurstone did not rank his subjects on a single scale of general aptitude. But when other investigators studied the profiles of his subjects, they detected a small tendency for those who excelled in one of the eight clusters to score well on the others. So, they concluded, there was still some evidence of a G factor" (Myers 423).
    • Many who have savant syndrome are also diagnosed with autism, although not all savants have autism, which mostly affects males, and 4 in 5 savants are males. (Myers)
    • some savants have virtually no language ability, yet can compute complex math problems instantly which suggests that humans actually have multiple intelligences rather than a single intelligence (Myers)
    • Savant syndrome is a condition in which a person otherwise limited in mental ability has an exceptional specific skill, such as in computation or drawing (Myers 425).
    • Alonzo Clemons can reproduce an exact bronze statue of any animal he sees, even of he just saw it briefly (Myers)
    • Kim Peek depends on his father for many basic needs but knows more than 7600 books by heart, and know all U.S. area codes, zip codes, and TV stations (Myers)
    • Leslie Lemke is blind, has never had piano lessons, yet he can play nearly any piece perfectly even after hearing it just once. (Myers)
    • Analytical(academic problem-solving) intelligence– assess by intelligence tests which present well-defined problems having a single right answer.
      • "Book Smart"
      • For example, this individual might display excellent test scores and grades; is able to solve formulaic problems.
    • Creative Intelligence- demonstrated in reacting adaptively to novel situations and generating novel ideas (Meyers)
      • Albert Einstein
      • For example, this would be someone like an artist who develops and new and creative process of doing art work.
    • Practical Intelligence- required for doing everyday tasks, which are frequently ill-defined, with multiple solutions. (Myers)
      • For example, fixing a car or a house
      • "Street Smart"
    • Traditional intelligence tests assess academic intelligence. They predict school grades reasonably well but do less well in predicting vocational success...Managerial success, for example, depends less on the academic abilities assessed by an intelligence test score (assuming the score is average or above) than on a shrewd ability to manage oneself, one's tasks, and other people. (Myers 425)
  • Those who demonstrate keen practical intelligence may or may not have distinguished themselves in school
  • Today's millionaires had average college grades; "a 2.92 undergraduate grade point average" - book ad, The Millionaire Mind
  • Sternberg and Richard Wagner's (1993, 1995) test of practical managerial intelligence measures whether the test-taker knows how to write effective memos, how to motivate people, when to delegate tasks and responsibilities, how to read people, and how to promote their own careers (Meyers 425)
  • Though Sternberg and Gardner vary in opinion regarding certain topics, they generally agree that multiple abilities can contribute to life success
  • Under Sternberg's/Gardner's influence, several teachers have been trained to acknowledge the differences in ability and to integrate multiple intelligence theory in their learning environments
  • Social Intelligence- the know-how involved in comprehending social situations and managing oneself successfully.
    • this is mostly based on ones way of viewing the situation, and how how believes they should act during a certain situation.
    • Ex. Seeing a car on the side of the road and pulling over and offering your help to the nice old lady that is standing beside it. Or to keep driving because instead of an old lady its a big scary looking guy with face tattoos and a prison uniform.
    • Called first by Nancy Cantor and John Kihlstrom (1987)
  • Emotional Intelligence- the ability to perceive, express, understand, and regulate emotions. It is a critical part of social intelligence. (Myers)
    • Emotionally intelligent people tend to be more self-aware(Myers)
    • Not necessarily related to academic aptitude (Myers 426).
    • Emotionally intelligent people can manage their emotions well and are not easily overwhelmed by negative emotions such as anger, depression, and/or anxiety.
    • An example of a person who may have emotional intelligence is a counselor
      • Social intelligence is the know-how involved in understanding social situations and managing oneself correctly. (Myers)
      • The fact that college grades can only predict work achievement moderately is consistent with the idea that academic and social intelligence are both distinct. (Myers)
  • They can delay gratitude and handle other people's emotions skillfully. (Myers)
  • They are emotionally smart, and thus often succeed in careers, marriages, and parenting where other academically smarter (but occasionally less intelligent) people fail. (Myers 426)
  • Emotional intelligence has 3 components: 1) the ability to perceive emotion. 2) the ability to understand emotions. 3) the ability to regulate emotions.
  • Women tend to be more emotionally intelligent than men.
  • Ex. - some people, even if they don't score high on standard intelligence tests, are gifted at perceiving, understanding, and expressing emotions(Myers)
  • The Mutifactor Emotional Intelligence Scale (MEIS) access the test takers ability to perceive emotion, understand emotion, and regulate emotion. (Myers)
    • perceive emotion- by recognizing emotions convoyed by various faces, musical excerpts, graphic designs and stories. (Myers)
    • understand emotion- by recognizing how emotions change over time, predicting differing emotions, and apprehending how emotions blend. (Myers)
  • example: the emotions of a driver whose car hit a dog chasing a stick and the emotions of the dog's owner.
    • regulate emotion- by rating alternate strategies that one could use when facing various real-life dilemmas. (Myers)
  • Our academic abilities are important and measurable through the use of intelligence tests. However, we require much more than simple academic abilities to be able to perform everyday tasks. This is often not able to be measured as easily by using intelligence tests (Myers).
  • Intelligence is most vital when it comes to mentally demanding jobs
  • However, those who meet with the most success in their vocations possess extra traits as well: conscientiousness, good connections, and vigorous charisma
  • Thus, high intelligence does more to get you into a profession (via the schools and training programs that take you there) than it does to make you successful once there (Meyers 427)
  • Primary Mental Ability
  • Louis Thrustone believed viewed intelligence as a general ability rather than individual areas, he focused his studies on 7 primary abilities
  1. verbal comprehension
  2. reasoning
  3. perceptual speed
  4. numerical ability
  5. word fluency
  6. associative memory
  7. spatial visualization
Intelligence and Creativity
Creativity- ability to produce novel and valuable ideas. (Myers); being able to produce new and meaningful ideas
  • Creative people have a solid base of knowledge and imaginative skills which allows them to see things in a different way and make connections (Myers).
  • it has been seen that those that are not glued to the pressures of social approval relativity show higher levels of creativity. This is because theit goal is not to seek approval, but to express their creativity.
  • People with high IQs may or may not be creative, which indicates that intelligence is only one component of creativity (Straub). According to Myers, beyond an intelligence score of about 120, the correlation between intelligence scores and creativity disappears.
  • For example, creative people such as architects and mathematicians normally score no higher on intelligence tests than their less creative peers which suggests that there is more to creativity than what intelligence tests reveal (Myers).
  • Based on 5 factors:

  1. Expertise- is well-developed base of knowledge. The more ideas, images, and phrases we have to work with, through our accumulated learning, the more chances we have to combine these mental building blocks in novel ways. (Myers)
  2. Imaginative thinking skills- Provide the ability to see things in a new ways, to recognize patterns, to make connections.(Myers) Having mastered the basic elements of a problem, we redefine or explore the problem in a new way. (Meyers 428)
  3. Venturesome personality- Tolerates ambiguity and risk,perseveres in overcoming obstacles, and seeks new experiences rather than following the pack. (Myers) Inventors, for example, have a willingness to persist after failures. Thomas Edison tried countless substances for his light bulb filament. (Meyers 429)
4. Intrinsic motivation- People will be most creative when they feel motivated primarily by the interest, enjoyment, satisfactions, and challenge of their work.(Myers)
  • Creative people focus not so much on extrinsic motivators such as meeting deadlines, impressing people, or making money as on the intrinsic pleasure and challenge of their work or hobby(Myers 429).
  • This is why turning something you wouldn't normally do for money, such as playing video games, into a job can be difficult. Once you start playing video games for money, you expect money every time you play. Playing video games stops being intrinsically motivated and becomes extrinsicly motivated .
  • 5 Extrinsic Motivation : motivation comes from something other than personal enjoymen. An example of this is homework. A student does not do homework because they want to, but because they have to.
  • 6. Crefative environment- Sparks, supports, and refines creative ideas (Myers). It has been found that most geniuses are not "lone geniuses" but are surrounded by colleagues that support, mentor, and challenge endeavors (Myers).
    • Analytical Intelligence- Assessed by intelligence tests, which present well-defined problems having a single right answer.
    • Creative Intelligence- Demonstrated in reacting adaptively to novel situations and generating novel ideas.
    • Practical Intelligence- Often required for every day tasks; which are frequently ill-defined, with multiple solutions (myers)
  • Traditional intelligence tests asses academic intelligence and predict your success in school.(Myers)
  • Gardner, Thurstone, and Sternberg agreed on the idea of multiple intelligences.
  • Ex. Sternberg and Wagner created a practical managerial intelligence test to measure how well people write memos, and perform other business tasks. People who score high on this test tend to make more money, and have higher ratings than those who didn't. Yet some of these high scorers only maintained a 2.92 college g.p.a. This suggests that while they may not be "book smart," they are intelligent in another way (Myers)
    • If intelligence does correlate with brain size, the cause could be differing genes, nutrition, environmental some combanations of this or perhaps something else.(Myers)
  • Intelligence is the ability to learn from experience, solve problems, and adapt to new situations (Myers)
  • Multiple Intelligence's- Gardner believes that we have multiple intelligences (Myers 424)
    • Word Smarts
    • Number Smarts
    • Music Smarts
    • Space Smarts
    • Body Smarts
    • Self Smarts
    • People Smarts
    • Nature Smart
  • Some examples of people that Gardner thought demonstrated the multiple types of intelligence were poet T. S. Eliot, scientist Albert Einstein, composer Igor Stravinsky, artist Pablo Picasso, dancer Martha Gram, psychiatrist Sigmund Freud, leader Mahatma Gandhi, and naturalist Charles Darwin. (Meyers 424).
  • Savant Syndrome- A condition in which a person with otherwise limited mental ability has an exceptional specific skill, such as in computation or drawing. People with this syndrome often score low on intelligence tests but have an island of brilliance - some incredible ability, as in computation, drawing, or musical memory. (Myers)
    • many of these people are diagnosed with autism as well.
    • Savants may have virtually no language ability, yet may be able to compute numbers as quickly as a computer or do other magnificent things. (Myers 424)
    • 4/5 savants are male.
    • An example of someone with savant syndrome would be Alonzo Clemons. Clemons can create "Perfect replicas" of any animal he briefly sees despite a developmental disability
    • Savants may have virtually no language ability, yet may be able to compute numbers as quickly and accurately as an electronic calculator, or identify almost instantly the day of the week that corresponds to any given date in history (Miller, 1999). (Myers 424)
  • Brain Function and Intelligence- "Searching for other explanations, Neuroscientists are studying the brains Functions" (Myers 430).
    • Processing Speed
    • ex: Those who recognize quickly that sink and wink are different words or that A and a share the same name, tend to score high in verbal ability. (Meyers 430).
    • Perceptual Speed
    • Neurological Speed
  • Psychologists agree that people have specific abilities, such as verbal and mathematical aptitudes. However, they debate whether a general intelligence factor runs through them all. Factor analysis and studies of special conditions, such as the savant syndrome, have identified clusters of mental aptitudes. (Myers)
Assessing Intelligence
  • Minnesota Multiphase Personality Inventory - the most widely researched and clinically used of all personality tests.
    • Are not predictive as they are reliable (Myers).
    • Aptitude is the capacity to learn. it is also a test designed to predict a persons future performance. (Myers)
    • Tests like the SAT are aptitude test because they attempt to predict a person's success in college.
    • the predictive power of aptitude scores lowers as a student moves up in greater education however its great in lower grades with a .6 correlation in test scores and grade scores
      • If we were to look for a correlation between american line'men body weight and their success on the field the relationship would become insignificant if were to narrow the range of weights to 260-300 pounds. So as the range of data considered narrows the predictive power diminishes as well. (Myers 436)
    • Vocabulary levels influence how well people do on their aptitude test.
    • Aptitude for learning or test taking influence the results on achievement test.
    • An achievement test is designed to asses what a person has learned. (Meyers)
    • Tests like the AP Exams are designed to test if a person knows the content that has been taught and is therefore an achievement test.
    • Wechsler also developed the WISC (Wechsler Intelligence Scale for Children) which is an IQ test for school-aged children. as well as for preschool children.
    • this test not only yields an overall intelligence score, but it alos shows separate "verbal" and "performance' scores. (Myers)
  • We must remember that intelligence test scores reflect only one aspect of personal competence; our practical and emotional intelligence matter also (Myers).
  • Projective Tests- ambiguous stimuli, open to interpretation (Talamo)
    • Ex: Rorshach Inkblot Test- sequence of inkblots. Participant are asked to observe and characterize. Psychologists use this test to examine a patient's characteristics and emotional functioning.
    • Ex: Thematic Apperception Test (TAT)- series of pictures of people in relationships with other people. Participants are asked to tell a story.
  • Power Tests- test abilities in certain areas. Usually extremely difficult. An ability is measured by the amount of difficulty that can be mastered rather than the speed of a performance.
  • Speed Tests- timed test, but with relatively easy questions
  • Matching Patterns: Block design puzzles test the ability to analyze pattern, Wechsler's individually administered intelligence tests comes in forms suited for adults (WAIS) and children (WISC). (Myers)

Test Construction
To be widely accepted, psychological tests must meet three criteria: They must be standardized, reliable, and valid. (Myers)
  • Standardization- defining meaningful scores by comparison with the performance of a pretested "standardization group" (Myers)
    • re-standardizing is necessary because of the Flynn Effect: which says that a population as a whole may have gotten smarter over the years so they must be re standardized
    • To standardize a test, we take a large sample of people to take the test and set their scores as the "standard" score.
    • It must be kept consistent with the current average, meaningful scores
  • Normal Curve- The symmetrical bell shaped curve that describes the distribution (frequency of occurence) of many physical and psychological attributes. Most scores fall near the average (mean), and fewer and fewer scores lie near the extremes (les than 5% of values lie above or below the given value). For example scores on an aptitude tend to form a normal, bell shaped curve.(Myers)
    • 68% of people lie within one standard deviation from the mean. (z-score)
    • 95% of people lie within two deviations from the mean.
    • 99.7% of people lie within three deviations from the mean
    • a good test must yield dependably consistent scores. To check reliability, researchers retest people using either the same test or a different form of it. If the results correlate, then the test is reliable. test-retest score(Myers)
    • Another alternative is for researchers to split a test in half and see whether scores from odd and even questions agree – split-half score
    • The higher the correlation between the test-retest or the split have scores, the higher the test's reliability is (Myers 436)
    • internal validity: degree to which the subject's results are due to the questions being asked and not another variable (Talamo 166)
    • external validity: degree to which results can be generalized to population of interest, such as the entire US or the world (Talamo 167)
    • Content Validity- the extent to which a test samples the behavior that is of interest.
    • criterion- the behavior that a test is designed to predict; thus,the measure used in defining whether the test has predictive validity.
    • Predictive Validity- also called criterion-related validity;success with which a test predicts the behavior it is designed to predict.
    • Reliability- extent to which a test yields consistent results and is assessed by consistency scores on:
    1. two halves, alternative forms and retests
    • When we validate a test using a wide range of people, it loses much of is predicted validity with a smaller range of people
    • assessed by computing the correlation between test scores and the criterion validity.
      • For example, we can look at the validity of the SAT. The SAT is suppose to measure how well we can perform at a college level but it shows no correlation after the first year of college on how well we can perform through our SAT score.
      • For example, if you use an inaccurate tape measure to measure heights your height report would have a high reliability but low validity.
  • Ex) The SAT and GRE score have a much higher correlation with each other than their intended criterion of school achievement. Their reliability greatly exceeds their predictive validity(Myers 438)
One way to glimpse the validity and significance of any test is to compare people who score at the two extremes of the normal curve. (Myers)

The Dynamics of Intelligence
Stability or Change?**
  • The stability of intelligence test scores increases with age (Myers)
  • studies by Joseph Fagan, Marc Bornstein, John Columbo, and others showed that 2-7 month old babies with a preference to view new pictures quickly tested higher on brain speed and intelligence up to 11 years later
  • Casual observation and intelligence tests before age 3 predict a child's future aptitude only minimally (Myers).
  • predicted scores tend to become fairly stable by age 7
  • By age 4, children's performance on intelligence tests begins to predict adolescent and adult scores (Myers).
    • Higher scoring adolescents tend to have been early readers, starting reading at about age 4 or age 5 (Myers).
  • Approximately 1% of the population have very low intelligence scores, experience difficulty adapting to the normal demands of independentlly, and are labelled as mentally retarded. (Straub)
  • Approximately 3-5% of children are labelled as "gifted". (Straub)
    • The segregation of separating children into gifted and nongifted educational tracks remains controversial. Critics of ability tracking contend that it does not result in higher achievement scores, that it lowers all students' self concepts and sometimes creates a self-fulfilling prophecy, and that it promotes segregation and prejudice. It is also based on the erroneous notion that giftedness is a single trait rather than any one of the many specific abilities. (Myers)
  • Down Syndrome
    • retardation and associated physical disorders caused by an extra chromosome in one’s genetic makeup (Myers).
    • before, many people who suffered from down syndrome were often institutionalize but now, many individuals with down syndrome succeed in having a job and caring for themselves
  • Heritability - proportion of variation among individuals that we can attribute to genes (Myers).
    • IQ scores and mental disorders such as down syndrome and mental retardation can be attributed to this.
    • Studies on twins found that identical twins reared in separate households still had similar IQ scores. Both fraternal twins reared together and identical twins reared together had a resulting heritabillity quotient of about .75 (The Princeton Review).
Mental Retardation- condition of limited mental ability, indicated by an intelligence score below 70 and difficulty adapting to the demands of life (Myers,439)
  • The Low Extreme - At one extreme are those whose intelligence test scores fall below 70. (Myers)
    • These extremes are developed through the standardization of scores and how far they are from the average scores of the population (mean). Scores that are multiple standard deviations from the mean are considered extremes
      • These people can lead fairly normal lives. (Myers)
      • Mental Age from 8 to 12. (Myers)
      • Children with mild retardation are educated in less restrictive environments, and many are mainstreamed into regular classrooms (Myers)
      • May learn academic skills up to sixth grade level. (Myers)
      • These people need supervision, but can still work jobs and lead somewhat normal lives. (Myers)
      • Mental age is around 3 to 7. (Myers)
      • Mental age between 0 and 2. (Myers)
      • learn to speak and preform simple work tasks under supervision. (Myers)
      • Require assistance aid and supervision
    • To be labeled as having mental retardation, a child must have both a low test score and difficulty adapting to the normal demands of independent living. (Myers)
    • * Mental retardation sometimes has a known physical cause. Down Syndrome, for example, is a disorder of varying severity caused by an extra chromosome in the person's genetic makeup. (Myers)
  • Earl Hunt did studies involving response time and quickness and how these aspects correlate with intelligence.
    • He noticed that individuals will , on average, have higher intelligence scores on the verbal portion of the test, if they are able to more rapidly recall details from their memory.
  • There has been observed a moderate to strong correlation (.4 to .5) between speed in processing information and a measurable IQ score.
  • Neurological differences have also been measured when comparing intelligence.
    • It has been observed that people with high IQs respond to even less sophisticated sensory information with more brain stimulation. Their brain records the details with more details and at a faster speed. This is observed by looking at possible an EEG displaying the brain waves.
  • Brain size, not just head size, has been measured through the use of MRIs. A correlation of .44 has been found when comparing brain size and intelligence, after the overall body size of individuals has been adjusted for. This means that individuals with larger brains, on average, tend to have higher IQs (Myers 430-431). [1]
Genetic Influences
  • Heritability is the proportion of variation among individuals that we can attribute to genes.
    • Heritability of any trait depends on the context or environment, in which that trait is being studied (Myers)
    • Across studies of twins, the intelligence test scores of identical twins reared together are virtually as similar as those of the same person taking the same test twice. (Myers)
    • Fraternal twins, who normally only share half their genes, have much less similar scores. (Myers)
    • Brain scans reveal that identical twins have very similar gray matter volume.(Myers)
    • Fraternal twins show that their brains are virtually the same in areas associated with verbal and spacial intelligence. (Myers)
    • 50-75% of the variation in intelligence within a group of people can be attributed to heredity. (Straub)
    • Remember, too, Genes and environment correlate (Myers)
- Variability depends on rage of populations and environments studied.

Environmental Influences: Genes make a difference. even if we were all raised in the same intellectually stimulating environment, we would have differing aptitudes. (Myers)
  • "...we also see that heredity doesn't tell the whole story" (Myers)
  • Research studies that compare children reared in neglectful environments- including those associated with poverty and malnutrition- with those who have been reared in normal environments point to the impact of environmental experiences on intelligence scores. Studies of early brain stimulation fostered by Head Start and other high quality preschool programs indicate that these enrichment programs can generate short term cognitive gains and long term positive effects (Myers)
  • the schooling effect- on test of nonverbal intelligence administered by Sorel Cahan and Nora Cohen of Hebrew University, older children within a grade tend to score slightly higher than their younger classmates. The large gap between the end of one line and the beginning of the next reflects the extra year of schooling among children who are virtually the same age.(Myers)
  • By William Dickens and James Flynn, he said that because of gene-environment correlation modest genetic advantages can be socially multiplied into big performance advantages. (Myers)

Group Differences
  • High-scoring people are more likely to attain high levels of education and income. (Myers)
    • In this case the level of education and income would be considered confounding variables and would have to be accounted for in order to get a representative aptitude test
    • Those who are rich i.e. Whites have a typically higher IQ score than African Americans.
    • Innate differences in the intelligence caused by cultural experiences
      • Cultural norms are responsible
    • Test is less valid for some groups than for others
      • ex. SAT scores predicts college achievement for one race but not of another
    • An example of ethnic difference would be that of North and South Korea. South Koreans tend to outscore North Koreans due to the poor environment North Koreans are raised in. North Koreans are very poor, and malnourished, hindering their intellectual growth.
  • There are two different kinds of bias concerning intelligence tests. One is that the tests detect not only innate differences in intelligence, but also the differences caused by cultural experiences. (Myers)
  • Intelligence tests are supposed to measure your developed abilities, which reflect, in part, your education
  • and experiences. (Myers)
  • Most experts do not consider the major aptitude tests to be significantly biased (Myers).
  • Aptitude tests are designed to predict future performance. They measure your capacity to learn new information, rather than measuring what you already know (Myers).
  • Stereotype threat is the phenomenon in which a person's concern that he or she will be evaluated based on a negative stereotype (as on aptitude test, for example), is actually followed by lower performance. (Myers)
    • test "scores of black students' verbal aptitude tests were lower when they took tests under conditions designed to make black students feel threatened." (Myers)
    • If you tell students that they probably won't succeed, this stereotype will eventually cause their performance to descend on both aptitude tests and in school (Myers).
    • They may detach their self-esteem from academics and may look for self-esteem elsewhere. (Myers)
    • Hispanics may feel immense pressure and score lower on a math test if tested with Asians, than if they only tested with Hispanics.
    • Women tend to score higher in math and science if men are not around.
  • The Mental Rotation Test - A test where you mentally rotate a shape to match the standard (question)
  • Steele concluded that if you tell students they probably won't succeed this stereotype will eventually erode their performance both on aptitude test and in school. (Myers)
  • Most researchers find that there is no gender gap between males and females intelligence scores, but most find these differences newsworthy (Myers).
  • Females are more sensitive to touch, smell, taste, and are more verbally fluent than boys (Myers)
  • In 20 of the 21 countries a study took place, males scored higher in math problem solving than girls (Myers).
    • Perhaps, males and females are "better" in math and language arts, respectively because of gender stereotypes. They decide to become interested in the academic field that their gender should be interested in.
  • Male high school seniors average about 45 points higher than girls on the 200-800 point SAT math test (Myers).
  • ...9 in 10 rated chess players and American architects, engineers, and map makers are men...(Myers 449).
  • It is important to remember that "intelligence test scores reflect only one aspect of personal competence" (Myers) and that it is important to take into account a person's practical and emotional intelligence, along with their talents and character (Myers).
  • Intelligence test scores are only one part of the picture of a whole person. They don't measure the abilities, talent, and commitment of, for example, people who devote their lives to helping others(Myers 451).
The Question of Bias
  • Knowing there are group differences in intelligence test scores leads us to wonder whether intelligence tests are biased (Myers 450)
  • The answer depends on two different definitions of bias
  • One meaning is that tests detect not only innate differences in intelligence but also differences caused by cultural experiences
  • Another meaning hinges on whether a test is less valid for some groups than for others

  1. ^ Myers, David G. Myers' Psychology for AP. Seventh ed. New York, NY: Worth, 2004. Print.