Measurements of intelligence (tests)
Wechsler tests - 4 scales
Theory Based Intelligence tests - fluid + crystal, 3 abilities
Achievement tests - Crystallised
Aptitude Tests - fluid
Wechsler tests - 4 scales+uses
4 scales measuring:
- Verbal comprehension
- Perceptual reasoning - pattern recognition
- Working memory
- Processing speed
Makes 4 scores, Overall IQ = combination of 4 scores
- used for assessing brain injury - working ability (most affects processing speed)
- useful for assessing impoverished/uneducated individuals
Using 4 scales allows for examining disparities between them - large gaps = trauma/impoverished environment
Theory Based Intelligence tests
specifically monitors Crystallised+fluid intelligence
e.g. Sternberg’s Triarchic Ability test - analytics, Creative, practical intel.
expects for each type of intel to not correlate - independent of one another
- results show abilities often are correlates = poor testing, overlap in measuring which components
Achievement tests
tests crystallised intelligence - tests the knowledge one has learnt so far
- good predictor of future academic attainment
- limitation: based on everyone having identical environmental academic support/exposure
Aptitude Tests
Test fluid intelligence uses puzzles/novel situations monitors problem-solving
- difficult to construct a test entirely independent of prior knowledge
- fairer - designed to measure intellectual potential independent of environment
- not necessarily applicable to real life success
3 Psychometric Standards
How we make sure all psychology (intelligence) tests follow same standards
- Reliability: consistency of measurement
- Validity: Construct/content Validity, Criterion-Related Validity
- Standardisation: norms/average comparison
3 types of reliability (in tests)
Test-retest reliability: consistency of measurement over time IQ should remain same if retaken
Internal Consistency: questions should be consistent between themselves in how they measure (an aspect) of intelligence, different sections should correlate
Inter-judge Reliability: different assessors interpret answers to the test to = same IQ
2 types of test Validity
Construct/content Validity: whether test is measuring intelligence or education level/culture
Criterion-Related Validity: Predictive validity - whether IQ is a good predictor of realise competence - correlate with school grades?
Deary et al. 2004 findings & explanations
longitudinal study on intelligence + life span
higher IQ at birth, lived longer, more so for women
causes:
- higher intelligence = less manual work jobs, better health, women work fewer labour jobs?
- higher intelligence correlates with a healthier brain, body - live longer
3 types of Test standardisation
Standardisation: internal validity, control testing proceedutres & development of norm - average score per demographic
Norm: average/baseline for a specific age group/ target population
Normal Distribution: higher frequency congregating around the average (bell curve)
The Flynn effect
average increase in IQ scores over past century (average:100)
causes:
- nutrition (height has increased too), advanced teaching, technology (more visual-spatial skills developed), or more attuned to answering those test questions
2 types of Testing conditions
Static testing: Same questions, conditions kept same between repeats of test (ignores how we learn from previous questions, educational backgrounds (which may impact score -not intelligence))
Dynamic testing: examiner interacts with individual, gives feedback after test, repeated and tested on their improvement (more reflective of diff types of intelligence, ability to learn - fairer as not limited by educational background)
Sternberg’s theory of successful intelligence & overcoming culture bias
- if you are adept in the necessary skills to survive in your culture, then you are intelligent
- Bc IQ tests are westernised, the things we test people on are the things we teach
- overcoming:
assess them on problems not tied to any culture - novel problem solving (e.g. Raven Matrixes - non-verbal reasoning)
create specific test for every culture
Impact of Genes/Heredity & Environment on intelligence?
- genes often play a bigger role than environment (if environment not impoverished)
- both contribute, rarely independently
- environment influences gene expression
- genes influence our environment (family)/ choice of environment
- genes account for 1/2-2/3 of IQ score variance (families have close IQ) but no singular intelligence gene
- environment is still 1/3 in identical twins tho - diff IQ
- education level impacts IQ - declines over the summer holidays
Impact of Genes/Heredity & Environment on Disabilities?
- genetic abnormalities account for 28% of disabilities
- extreme cases caused by mutations, not hereditary
Other causes: - O2 deprivation at birth
- drugs/alcohol taken/ diseases by mother
- 70-80% no clear biological cause
