Topic 9: intelligence + psychometric assessment Flashcards
Define intelligence
Hypothetical mental ability = enables people to direct thinking + adapt to circumstances = learn from experiences
Explain the theory of intelligence by Francis Galton
- Proposed the theory of hereditary genius = that there is heritability in the ability of genius
- Variation in abilities of the population
- Variations are inherited
- Nature vs nurture
- 1st to use questionnaires
Explain the theory of intelligence by Alfred Binet + Theodore Simon
- Identified typical intelligence for ages
- Developed intelligence scale = differentiate between chronological age + mental age
- Developed norms of achievements at each age stage = average/below average/high intelligence
What is the formula for calculating IQ?
(Mental age / Chronological age) * 100 = IQ
Define IQ
- Intelligence quotient
- It is the index of intelligence derived from tests
- Modern times = calculated using percentile rankings = converted to equivalent IQ scores onto a normal distribution curve
Explain general intelligence by Charles Spearman
- Proposed 2-factor theory of intelligence
- 2 factors = g + s
- g = general intelligence = everyone has
- s = special abilities = differentiates us from each other + extend of abilities
Explain general intelligence by Catell
- Crystallised intelligence = learn utilizing previous experiences = when older
- Fluid intelligence = learn as we go = when younger
Explain modern theory of intelligence by Gardner
- There are multiple intelligences rather than a general intelligence
- Intelligence linked to:
1) Linguistics
2) Musical
3) Mathematical
4) Spatial
5) Kinesthetic
6) Intrapersonal
7) Interpersonal
What are the characteristics of an intelligence test?
- Must be valid = measure what it’s supposed to measure = made sure by intercorrelating between tests
- Must be reliable = consistent result when repeated yourself and by others
What are the forms of intelligence in IQ tests?
1) Verbal = ability to comprehend + solve language-based problems
2) Non-verbal = ability to solve visual/spatial problems
Give examples of verbal subtests in Wechsler intelligence scale for adults
- Vocab
- Similarities
- Arithmatic
- Digit span
- Information
- Comprehension
- Letter number sequencing
Give examples of non-verbal subtests in Wechsler intelligence scale for adults
- Picture completion
- Digit symbol coding
- Block design
- Matrix reasoning
- Picture arrangement
- Symbol search
- Object assembly
Describe the bell-shaped IQ curve
- 95% within +/- 2 standard deviations of mean = 70-130
- 68% of population within 1 standard deviation of mean
- Average = +/- 1 standard deviation of mean = 85-115
Describe the range of IQs
- > 130 = Very Superior
- 120-129 = Superior
- 110-119 = High average
- 90-109 = Average
- 80-89 = Low average
- 70-79 = Borderline
- < 70 = Learning disabilities
- 55-70 = Mild LD
- 40-54 = Moderate LD
- 25-39 = Severe LD
- < 25 = Profound LD
What are the common intelligence scales?
- Wechsler scales = WAIS + WASI + WISC + WPPSI
- Raven’s progressive matrices = non-verbal
- Cattell’s culture fair IQ test
- National adult reading test
- Bayley scales of infant/toddler development
Explain the clinical uses of IQ tests
- Diagnosing + quantifying extent of learning disabilities = utilizing abilities and not force to learn things they are not able to
- Diagnosing + characterizing which specific learning difficulty
- Assessing intellectual impairment following trauma
What are extraneous influences on IQ scores?
- Familiarity with concepts + material
- Motivation to do well
- Distraction
- Way test administered e.g. not tested according to same manual + test not in mother tongue
- Sensory issues
- Cultural issues e.g. different world views
What are internal influences on IQ scores?
- Emotional state e.g. anxiety + bereavement
- Physical illness
- Mental illness e.g. schizophrenia
Describe the gender differences in IQ scores
- Test designed to reduce sex differences
- Males better at performance tasks
- Females better at verbal tasks
- Greater variation in male scores = more spread out with more at extreme ends
- Female scores cluster around mean
Describe the stability in scoring of IQ tests
- Testing in 1921 Scotland of 11 year olds + re-tested at 80
- Scores at 11 similar to 80 = either low/medium/high
- Low IQ scores at 11 associated with:
> Mortality
> More likely to get lung cancer
> More likely to experience psychiatric illness + dementia
Describe the nature vs nurture of intelligence
- Heritability = proportion of observed variation in a trait within a population that can be attributed to genetic variation
- Heritability isn’t % of intelligence by genetics BUT how much genetic difference contributes to variations in intelligence while other % is due to environmental factors
- Heritability in UK = 40-70%
- To see the impact of genetic variability = make environment consistent = any change will be due to genetics
What are the environmental influences on intelligence?
- Poor nutrition
- Environmental toxins
- Exposure to drugs in utero
- Lack of exposure to intellectually stimulating environment in childhood
- Neurological injury/disease
- Genetic disorder affecting brain development
Describe the effect of poor nutrition on intelligence
- Children in Guatemalan village = undernourished
- Given protein diet for few years
- 10 years later children scored higher in school than compared to control
Describe the effect of environmental toxins on intelligence
- Blood lead levels of children growing near smelting plants were negatively correlated with intelligence tests throughout childhood
- Higher lead in blood = IQ 7.2 points lower
