Assessment of Intelligence Flashcards
Brief history - Galton 1980
Cousin of Charles Darwin
-Wrote ‘The Hereditary Genius of Mankind
’-Used reaction times, hearing acuity etc
-Main contribution – operationalised intelligence
Alfred Binet (1904)
French psychologist
- How to identify pupils who might need more assistance…?
- Worked with Theodore Simon to produce the Binet-Simon test
- Original hypothesis – children of a certain age ‘should’ be able to do certain ‘things’
- ‘Things’ – measured judgment, comprehension, and reasoning which Binet deemed the key characteristics of intelligence
- Created a 30 item test for each age level from three years to 10 years
Binet-Simon 1911
Mental age (MA) vs Chronological age (CA)
- Most pupils performed at the ‘average’, some pupils performed above their age expectation, some below
- Published in 1911 for 3 to 10 year olds, plus 12 and 15 year olds and adults
- Main problem – separate test required for each age level
Stanford-Binet 1916
To the US (obviously) and Terman (adapted for US students)
- Five features of cognitive ability - fluid reasoning, knowledge, quantitative reasoning, visual-spatial processing and working memory
- Both verbal and nonverbal responses are measured
- Still used today
Stern (1912)
German psychologist-
Worked with larger number of pupils using the Binet-Simon tests
- Noticed that the ratio (MA/CAx100) remained relatively consistent for individuals
- First suggested IQ using this formula
- Thus, 10 year old (CA) with 12 year MA would have an IQ of 12/10x100 = 1
Wechsler 1939
First assessment tool was called the Wechsler-Bellevue Scale (1939)
- Developed three scales – WPPSI (ages 2:6 – 7:6), WISC (6 – 16) and the WAIS (16 and up)
- Revised over the years – WPPSI-IV (2012), WISC-V (2014), WAIS-IV (2008, WAIS-V, expected soon)
- The most utilised tests of IQ in the world
Wechsler’s major contributions
designed so that all people of all ages could take them
- Used a Deviation IQ
- IQ not based on ‘ages’ but on actual scores
- Deviation IQ = (Actual score/Expected score for that age) x 100
- Measured by how much a person ‘deviated’ from the average (of 100
Wechslers major contributions
calculations
standardisation – determining the ‘expected score’ for any age
- Used Stratified sampling – people at all ages and in all demographic groups - sex, region, socio-economic
- Used ‘norms’ to compare a person’s score to the mean for that person’s group, set at 100-Used the old notion of average IQ = 100
- Found that IQ is normally distributed – mean = 100, SD = 15
normally distributed IQ scores - normal distributions
67% of the population fall + 1SD from the mean, between 85 (low average) and 115 (high average)
- 95% of the population fall + 2SD from the mean, between 70 and 130
- 5% of the population fall outside these extremes
normally distributed IQ scores - in the extremes
people with IQ’s above 130 are considered to be ‘gifted’
- Langan, an American horse rancher, has an IQ score around 200
- Einstein and Hawking had IQ’s of 160 (Dr Field has an IQ of…? )
- Scores below 70 indicate intellectual disability, marked by substantial motor, cognitive, and speech delays
- Some of these disabilities are the product of genetic mutations, eg Down syndrome
- In Savant syndrome individuals with significant mental disabilities, demonstrate far above average abilities such as incredible memory, rapid mathematical or calendar calculations or advanced musical talent
reliability of assessment toosl
reliability means that they are consistent over time
- Three common types – test-retest, alternate form and internal consistency measures
- For test-retest, if you take a test at two different points in time, there will be very little change in performance or, in the case of intelligence tests, IQ score-
Scores will fluctuate when taking the same test on different occasions or different tests at the same age
-IQ tests demonstrate high reliability (Tuma & Appelbaum, 1980)
validity of assessment tools
validity means that the test is measuring what it is supposed to measure-
Four common types – Face, Concurrent, Predictive and Construct
-However, intelligence tests are really measuring IQ
– and they do that very well-The main question is whether an IQ score equates to Intelligence..
construct validity
higher scores intelligence tests predict
- Higher education
- Better qualification
- Higher socio-economic standing
- Better job performance
- Longer life
- Higher IQ scores predicted superior job performance better than CV, qualifications, previous experience, interview findings (Hunter & Hunter, 1984)
- However, these relationships are correlational rather than causative
issues in the assessment of intelligence
critics claim that IQ tests are biased in favour of white, middle-class people
- Created by western psychologists (primarily) to measure euro-centric values
- Negative stereotypes about a person’s ethnicity, gender, or age may cause the person to suffer a variety of ‘stereotype threats’
- Doubts about their own abilities can create anxiety that result in lower scores
culture specifcity - cross cultural issues
majority of the world’s population does not reside in Europe or North America
- Different cultures hold different values and have different perceptions of intelligence, so is it fair to have one universal marker of this increasingly complex concept
- Kenyan parents defined intelligence as the “ability to do without being told what needed to be done around the homestead” (Harkness et al., 1992)
- Ugandans define intelligent people as “being slow in thought and action”. Compare this to the American and European emphasis on speed (Wober, 1974)
- Intelligence takes many forms, ranging from country to country and culture to culture
- IQ tests have high reliability and validity, however understanding the role of culture is very important in forming the bigger picture of an individual’s intelligence
- IQ tests accurately measure academic intelligence in the West, but more research must be done to discern whether they truly measure practical or general intelligence in all cultures