Instruct: Given a question, retrieve passages that can help answer the question.
Query: When was the first IQ test introduced?
Alfred Binet (French:[binɛ]; July 8, 1857– October 18, 1911) was a French psychologist who invented the first practical IQ test, the Binet–Simon test.[2] In 1904, the French Ministry of Education asked psychologist Alfred Binet to devise a method that would determine which students did not learn effectively from regular classroom instruction so they could be given remedial work. Along with his collaborator Théodore Simon, Binet published revisions of his test in 1908 and 1911, the last of which appeared just before his death.
In 1986, Frearson and Hans Eysenck conducted an experiment in which they assessed participants on various intelligence tests including Jensen's Choice RT, IQ, and a “new” Odd-Man-Out RT test. In their experiment they found that the Odd- Man-Out RT test was capable of producing “measures that were reliable and correlate well with an individual’s IQ." An interesting result from the experiment was that there was no difference in the correlation between the Odd-Man-Out RT test and IQ when displays were presented in a more difficult manner. For example, a more difficult display of the Odd Man Out RT test would mean the difference in the distance between the odd man out and the two stimuli placed closer together was less notable (x000x00x being more difficult than xx0000x0). The expectation would be that the difficulty of a display would affect the correlation between Odd-Man-Out RT test and IQ. However, this was not the case. In addition, they discovered that the position of the pattern in the layout did not play a role in one's reaction time. In another experiment done by Diascro and Brody (1994), the results showed that when the complexity of the Odd Man Out RT test was increased (by comparing more distances), the correlation between the individual's performance on the test and their intelligence (measured by an IQ test) was higher. They also found that the reaction times were longer and that individuals made mistakes more often with this more complex version of the Odd-Man-Out RT test.
The Flynn effect is the substantial and long-sustained increase in both fluid and crystallized intelligence test scores that were measured in many parts of the world over the 20th century. When intelligence quotient (IQ) tests are initially standardized using a sample of test-takers, by convention the average of the test results is set to 100 and their standard deviation is set to 15 or 16 IQ points. When IQ tests are revised, they are again standardized using a new sample of test-takers, usually born more recently than the first. Again, the average result is set to 100. However, when the new test subjects take the older tests, in almost every case their average scores are significantly above 100.
All IQ tests show variation in scores even when the same person takes the same test over and over again. IQ scores also differ for a test-taker taking tests from more than one publisher at the same age. The various test publishers do not use uniform names or definitions for IQ score classifications.
No professionally designed and validated IQ test claims to distinguish test-takers at a one-in-a-million level of rarity of score. The standard score range of most currently normed IQ tests is from IQ 40 to IQ 160. A score of 160 corresponds to a rarity of about 1 person in 30,000 (leaving aside the issue of error of measurement common to all IQ tests), which falls short of the Mega Society's 1 in a million requirement. IQ scores above this level are dubious as there are insufficient normative cases upon which to base a statistically justified rank-ordering. High IQ scores are less reliable than IQ scores nearer to the population median.
Kingswood Training School administered diagnostic tests to Bentley during the time of his detention there. In December 1948 (when he was 15½ years old), his mental age was estimated at 10 years, 4 months, when he scored 66 on an IQ test. Kingswood staff reported him to be "lazy, indifferent, voluble and of the 'wise guy' type", whilst a court described as "indifferent, smug, self-satisfied and ready to tell tales". After his arrest in November 1952, further IQ tests were administered to him at Brixton Prison. He was described there as "borderline feeble-minded", with a verbal score of 71, a performance IQ of 87 and a full scale IQ of 77.
An intelligence quotient (IQ) is a total score derived from several standardized tests designed to assess human intelligence. The abbreviation "IQ" was coined by the psychologist William Stern for the German term "Intelligenzquotient", his term for a scoring method for intelligence tests at University of Breslau he advocated in a 1912 book. Historically, IQ is a score obtained by dividing a person's mental age score, obtained by administering an intelligence test, by the person's chronological age, both expressed in terms of years and months. The resulting fraction is multiplied by 100 to obtain the IQ score. When current IQ tests were developed, the median raw score of the norming sample is defined as IQ 100 and scores each standard deviation (SD) up or down are defined as 15 IQ points greater or less, although this was not always so historically. By this definition, approximately two-thirds of the population scores are between IQ 85 and IQ 115. About 2.5 percent of the population scores above 130, and 2.5 percent below 70.
IQ tests generally are reliable enough that most people ages ten and older have similar IQ scores throughout life. Still, some individuals score very differently when taking the same test at different times or when taking more than one kind of IQ test at the same age. For example, many children in the famous longitudinal Genetic Studies of Genius begun in 1921 by Lewis Terman showed declines in IQ as they grew up. Terman recruited school pupils based on referrals from teachers, and gave them his Stanford–Binet IQ test. Children with an IQ above 140 by that test were included in the study. There were 643 children in the main study group. When the students who could be contacted again (503 students) were retested at high school age, they were found to have dropped 9 IQ points on average in Stanford–Binet IQ. More than two dozen children dropped by 15 IQ points and six by 25 points or more. Yet parents of those children thought that the children were still as bright as ever, or even brighter.
The first English-language IQ test, the Stanford–Binet Intelligence Scales, was adapted from a test battery designed for school placement by Alfred Binet in France. Lewis Terman adapted Binet's test and promoted it as a test measuring "general intelligence." Terman's test was the first widely used mental test to report scores in "intelligence quotient" form ("mental age" divided by chronological age, multiplied by 100). Current tests are scored in "deviation IQ" form, with a performance level by a test-taker two standard deviations below the median score for the test-taker's age group defined as IQ 70. Until the most recent revision of diagnostic standards, an IQ of 70 or below was a primary factor for intellectual disability diagnosis, and IQ scores were used to categorize degrees of intellectual disability.
The current scoring method for all IQ tests is the "deviation IQ". In this method, an IQ score of 100 means that the test-taker's performance on the test is at the median level of performance in the sample of test-takers of about the same age used to norm the test. An IQ score of 115 means performance one standard deviation above the median, a score of 85 performance, one standard deviation below the median, and so on. Lewis Terman and other early developers of IQ tests noticed that most child IQ scores come out to approximately the same number by either procedure. Deviation IQs are now used for standard scoring of all IQ tests in large part because they allow a consistent definition of IQ for both children and adults. By the current "deviation IQ" definition of IQ test standard scores, about two-thirds of all test-takers obtain scores from 85 to 115, and about 5 percent of the population scores above 125.
As long ago as 1937, Lewis Terman pointed out that error of estimation in IQ scoring increases as IQ score increases, so that there is less and less certainty about assigning a test-taker to one band of scores or another as one looks at higher bands. Current IQ tests also have large error bands for high IQ scores. As an underlying reality, such distinctions as those between "exceptionally gifted" and "profoundly gifted" have never been well established. All longitudinal studies of IQ have shown that test-takers can bounce up and down in score, and thus switch up and down in rank order as compared to one another, over the course of childhood. Some test-givers claim that IQ classification categories such as "profoundly gifted" are meaningful, but those are based on the obsolete Stanford–Binet Third Revision (Form L-M) test. The highest reported standard score for most IQ tests is IQ 160, approximately the 99.997th percentile (leaving aside the issue of the considerable error in measurement at that level of IQ on any IQ test). IQ scores above this level are dubious as there are insufficient normative cases upon which to base a statistically justified rank-ordering. Moreover, there has never been any validation of the Stanford–Binet L-M on adult populations, and there is no trace of such terminology in the writings of Lewis Terman. Although two current tests attempt to provide "extended norms" that allow for classification of different levels of giftedness, those norms are not based on well validated data.
Originally the standardized test was made of essays and was not intended for widespread testing. French psychologist Alfred Binet begins developing a standardized test of intelligence, work that would eventually be incorporated into a version of the modern IQ test, dubbed the Stanford-Binet Intelligence Test. The College Board then designed the SAT(Scholar Aptitude Test) in 1926 for a broader IQ test. Notably, the Army IQ tests were what the first SAT test was based on in order to determine a student’s intelligence, problem solving skills, and critical thinking.[14] In 1959, Everett Lindquist offered the ACT (American College Testing) for the first time.[15] The ACT currently includes 4 main sections with multiple choice questions to test English, mathematics, reading, and science, plus an optional writing section.[16]
In current medical diagnosis, IQ scores alone are not conclusive for a finding of intellectual disability. Recently adopted diagnostic standards place the major emphasis on the adaptive behavior of each individual, with IQ score just being one factor in diagnosis in addition to adaptive behavior scales, and no category of intellectual disability being defined primarily by IQ scores. Psychologists point out that evidence from IQ testing should always be used with other assessment evidence in mind: ""In the end, any and all interpretations of test performance gain diagnostic meaning when they are corroborated by other data sources and when they are empirically or logically related to the area or areas of difficulty specified in the referral.""
The Wechsler intelligence scales were originally developed from earlier intelligence scales by David Wechsler. The first Wechsler test published was the Wechsler–Bellevue Scale in 1939. The Wechsler IQ tests for children and for adults are the most frequently used individual IQ tests in the English-speaking world and in their translated versions are perhaps the most widely used IQ tests worldwide. The Wechsler tests have long been regarded as the "gold standard" in IQ testing. The Wechsler Adult Intelligence Scale—Fourth Edition (WAIS–IV) was published in 2008 by The Psychological Corporation. The Wechsler Intelligence Scale for Children—Fifth Edition (WISC–V) was published in 2014 by The Psychological Corporation, and the Wechsler Preschool and Primary Scale of Intelligence—Fourth Edition (WPPSI–IV) was published in 2012 by The Psychological Corporation. Like all current IQ tests, the Wechsler tests report a "deviation IQ" as the standard score for the full-scale IQ, with the norming sample median raw score defined as IQ 100 and a score one standard deviation higher defined as IQ 115 (and one deviation lower defined as IQ 85).
Test Australia: The National IQ Test is an Australian television show that aired on the Nine Network on 6 August 2002. The program was hosted by Eddie McGuire and Catriona Rowntree and ranked as the most watched Australian television show for 2002. The program, which allowed viewers to obtain a score on a Intelligence quotient (IQ) test while the show aired, was the first of its kind in Australia. It was also the first time an IQ test was available to an entire continent in one night. McGuire returned to host versions of the show in 2003 and 2010.
One of the criteria used in identification may be an IQ test score. Until the late 1960s, when “giftedness” was defined by an IQ score, a school district simply set an arbitrary score (usually in the 130 range) and a student either did or did not “make the cut”. It is no longer accepted today in academic circles; however, it's still used by many school districts because it is simple and not entirely without merit. Although a high IQ score is not the sole indicator of giftedness, usually if a student has a very high IQ, that is a significant indicator of high academic potential. Because of this consideration, if a student scores highly on an IQ test, but performs at an average or below average level academically, school officials may think that this issue warrants further investigation as an example of underachievement. However, scholars of educational testing point out that a test-taker's scores on any two tests may vary, so a lower score on an achievement test than on an IQ test neither necessarily indicates that the test-taker is underachieving nor necessarily that the school curriculum is under challenging.
IQ classifications for individuals also vary because category labels for IQ score ranges are specific to each brand of test. The test publishers do not have a uniform practice of labeling IQ score ranges, nor do they have a consistent practice of dividing up IQ score ranges into categories of the same size or with the same boundary scores. Thus psychologists should specify which test was given when reporting a test-taker's IQ. Psychologists and IQ test authors recommend that psychologists adopt the terminology of each test publisher when reporting IQ score ranges.
Traditional IQ tests observe the test-taker's performance in a standardized battery of samples of behavior. The resulting IQ standard score is the subject of much investigation as psychologists check correlations between IQ and other life outcomes. The Wechsler IQ tests for adults and for children have long been regarded as the "gold standard" in IQ testing.
A series of studies by Joseph Fagan and Cynthia Holland measured the effect of prior exposure to the kind of cognitive tasks posed in IQ tests on test performance. Assuming that the IQ gap was the result of lower exposure to tasks using the cognitive functions usually found in IQ tests among African American test takes, they prepared a group of African Americans in this type of tasks before taking an IQ test. The researchers found that there was no subsequent difference in performance between the African-Americans and white test takers. Daley and Onwuegbuzie conclude that Fagan and Holland demonstrate that "differences in knowledge between blacks and whites for intelligence test items can be erased when equal opportunity is provided for exposure to the information to be tested". A similar argument is made by David Marks who argues that IQ differences correlate well with differences in literacy suggesting that developing literacy skills through education causes an increase in IQ test performance.
There are a variety of individually administered IQ tests in use in the English-speaking world. Not all report test results as "IQ", but most now report a standard score with a median score level of 100. When a test-taker scores higher or lower than the median score, the score is indicated as 15 standard score points higher or lower for each standard deviation difference higher or lower in the test-taker's performance on the test item content.
Psychometricians generally regard IQ tests as having high statistical reliability. A high reliability implies that – although test-takers may have varying scores when taking the same test on differing occasions, and although they may have varying scores when taking different IQ tests at the same age – the scores generally agree with one another and across time. Like all statistical quantities, any particular estimate of IQ has an associated standard error that measures uncertainty about the estimate. For modern tests, the standard error of measurement is about three points . Clinical psychologists generally regard IQ scores as having sufficient statistical validity for many clinical purposes. In a survey of 661 randomly sampled psychologists and educational researchers, published in 1988, Mark Snyderman and Stanley Rothman reported a general consensus supporting the validity of IQ testing. "On the whole, scholars with any expertise in the area of intelligence and intelligence testing (defined very broadly) share a common view of the most important components of intelligence, and are convinced that it can be measured with some degree of accuracy." Almost all respondents picked out abstract reasoning, ability to solve problems and ability to acquire knowledge as the most important elements.
Since the early 20th century, raw scores on IQ tests have increased in most parts of the world. When a new version of an IQ test is normed, the standard scoring is set so performance at the population median results in a score of IQ 100. The phenomenon of rising raw score performance means if test-takers are scored by a constant standard scoring rule, IQ test scores have been rising at an average rate of around three IQ points per decade. This phenomenon was named the Flynn effect in the book "The Bell Curve" after James R. Flynn, the author who did the most to bring this phenomenon to the attention of psychologists.
Kaufman described how Marks tested these predictions by looking at samples representative of whole populations (rather than individuals), and used ecological methods to compute statistical associations between IQ and literacy rates across different countries. Kaufman's (2010) review suggested that Marks' findings were completely consistent with the predictions: (i) The higher the literacy rate of a population, the higher that population's mean IQ, and the higher that population's mean IQ, the higher the literacy rate of that population. (ii) When literacy rates declined, mean IQ also declined, a reversed Flynn Effect. (iii) Unequal improvements occurred across the entire IQ spectrum with the greatest increases in the lower half of the IQ distribution. Kaufman pointed out that the evidence suggested that both the Flynn Effect and racial/national IQ differences showed the largest effects of literacy on verbal tests of intelligence, with the perceptual tests of intelligence showing no consistent pattern.
The average difference in IQ scores between the testing at age 7 and testing at age 17, seen in all groups, may be due to the use of different IQ tests. The original study used Stanford–Binet Form L-M, WISC or WAIS tests, depending on age, while the follow-up used WISC-R or WAIS-R. Weinberg, Scarr and Waldman point describe the effect of this change in test:
Declines in IQ scores have been documented when individuals are retested on a revised form of an original measure, as well as when a test used at a first administration was normed earlier than a test used at a subsequent administration (see Flynn, 1984, for a review). For example, the decline in Full-Scale IQ score from the WAIS to the WAIS-R averaged 6.8 points across a number of studies (reviewed by Sattler, 1988) and was 7.5 points in a sample of 72 35- to 44-year-olds tested as part of the standardization of the WAIS-R (Wechsler, 1981). This is precisely the test combination used for adoptive parents in our study.
Furthermore, the data needed to be corrected for the Flynn effect as stated by Ulrich Neisser:
Furthermore, he dismissed the proposition that an IQ score measures the general intelligence ("g" factor) of a person, because cognitive ability tests (IQ tests) present different types of questions, and the responses tend to form clusters of intellectual acumen. That is, different questions, and the answers to them, yield different scores—which indicate that an IQ test is a combination method of different examinations of different things. As such, Gould proposed that IQ-test proponents assume the existence of "general intelligence" as a discrete quality within the human mind, and thus they analyze the IQ-test data to produce an IQ number that establishes the definitive general intelligence of each man and of each woman. Hence, Gould dismissed the IQ number as an erroneous artifact of the statistical mathematics applied to the raw IQ-test data, especially because psychometric data can be variously analyzed to produce multiple IQ scores.
Lewis Terman, developer of the Stanford–Binet Intelligence Scales, based his English-language Stanford–Binet IQ test on the French-language Binet–Simon test developed by Alfred Binet. Terman believed his test measured the "general intelligence" construct advocated by Charles Spearman (1904). Terman differed from Binet in reporting scores on his test in the form of intelligence quotient ("mental age" divided by chronological age) scores after the 1912 suggestion of German psychologist William Stern. Terman chose the category names for score levels on the Stanford–Binet test. When he first chose classification for score levels, he relied partly on the usage of earlier authors who wrote, before the existence of IQ tests, on topics such as individuals unable to care for themselves in independent adult life. Terman's first version of the Stanford–Binet was based on norming samples that included only white, American-born subjects, mostly from California, Nevada, and Oregon.