Intelligence and IQ testing Flashcards
What types of tasks are performed in IQ test?
Generally, IQ tests are composits of a variety of different tasks including:
- Vocabulary
- Arithmatics
- Visual puzzules
- Comprehension tasks
etc.
How are IQ score calculated for children in the Binet test?
- IQ = Mental age/Chronological age x 100
- IQ >100: Child has greater mental age than chronological age (more capable than cohort)
- IQ < 100: Child has lesser mental age than chronological age (less capable than cohort)
Why can adult IQ scores not be calculated in the same way as children (using mental and chronological age)?
- The cognitive ability of children improves (correlated) with chronological age, so the comparison between ‘mental age’ and ‘chronological age’ is relevant.
- In adults on the other hand, there isn’t a general correclation between chronological age and mental age.
How are adult IQ scores calculated using the Wechsler method?
- Mean score from cohort is set to 100 and ±15 points is equivalent to ±1 sd.
- Score is a measure of deviation from population.
What types of correlations should be seen between scores in a good IQ test?
- Scores from all categories should correlate with each other, showing that they are all related to each other.
- Score of specific IQ test should also correlate with scores from other good IQ tests.
- Indicates that tests are indeed measuring the same underlying variable of ‘intelligence’.
What are the different types of tests in Wechser’s IQ test?
- Performance IQ
- Verbal IQ
What are the tests used to assess performance IQ?
- Picture completion
- Picture rearrangement
- Object assembly
- Digit symbol
- Block design
What are the tests used to assess verbal IQ?
- Vocabulary
- Similarities
- Information
- Comprehension
- Arithmatics
- Digit span
What is heritability?
- Proportion of variance in a population of a trait that is due to genetic variation.
- Heritability is variable depending on the proportional effects of environmental factors. Hor example, when there are no environmental differences, the heritability is 1, as all variation must be due to genetics.
What is a high heritability trait?
Variation in a trait is not much affectd by current environmental factors.
What is a low heritability trait?
Variation in the trait is highly affected by current environmental factors.
How can heritability of IQ be measured?
Studying twins who have been raised separately from birth in different environments.
What are the results of heritability studies on IQ?
IQ is highly heritable as there is strong correlation between IQs of twins in different environments, suggesting that environments have little influence over IQ.
What are the arguments against heritability hypothesis of IQ?
- IQ is related to some confounding environmental factor.
- Twin studies are limited because many separated twins live close to each other in very similar environments.
How can reliability of IQ tests be measured?
- Internal consistency reliability: There is correlation between different sub-categories in IQ test.
- Test-retest reliability: There is the same correlation betweem the scores of the same group of people who sit multiple tests.