1. Psychometrics
Dr Jacqui McKechnie

2. Psychometric Tests General Tests WAIS and WISC
Specific Tests BDI and BAI
Personality Tests MMPI-II
Projective Tests Rorschach inkblot test

3. Theories of Intelligence
Spearman (1904)
Two-Factor Theory of Intelligence.
1) a general factor - g factor
2) specific factors
Guildford (1967)
120 different factors
Thurstone (1938)
7 ‘primary mental abilities’
Goleman (1995)
Emotional Intelligence
Gardner (1983)
Multiple intelligence - 6 types

4. Crystallised Intelligence
specific knowledge e.g. vocabulary
increases with age
depends on level of education
influenced by environmental factors

5. Fluid Intelligence basic powers of reasoning and problem solving
Cattell’s IQ test
starts to decline at 21 years
falls steeply after 60 years
influenced by genetic factors

6. Intelligence Tests
Binet & Simon (1905) - developed tests for children based on concept of mental age.
• IQ not fixed
• would help to direct education
• should not be used as a label
Stanford - Binet Scale adapted for American children by Terman & Yerkes.

7. It was used for classification
• IQ score - fixed
• could rank order individuals
• differences attributed to innate genetics
Intelligence Quotient
mental age
x 100
chronological age

8. Adults
standardised to make the average result 100
This makes the average IQ 100.
95% score
68% score

9. Types of IQ test British Ability Scales developed in 1970’s
Individual tests:-
WAIS - Weschler Adult Intelligence Scale
WISC - Weschler Intelligence Scale for Children
Verbal - vocabulary, arithmetic, reasoning
Performance - picture completion, block design

17. Group:- AH test - Alice Heim
Group comparison, economical
Sample Questions
Give the next but one member of the series:
1/2, /5, /8, / ……
Here are words denoting five generations in one family. Which has two, and only two, younger relations:
grandmother, great-grandson, son, father, grandson
Here is to there as these is to:
yonder, that, others, those, this
11/17

18. Reliability and Validity
Selection
There may be biases inherent in the items chosen.
Reliability
It is important that if the same people are tested they give the same results.
• Test-retest method
• Split-half reliability
• Alternate-forms reliability

19. Validity
Do tests measure what they claim to measure?
Does the test result predict performance?
• Predictive validity
• Face validity
• Content validity
• Concurrent validity
• Construct validity
• Consensual validity

20. Response Bias
How do we make sure that the test isn’t producing a tendency to answer the questions in one way rather than another?
• Questions themselves could be producing the answers.
• The way a question is phrased can also produce a response.
• People try to present themselves in the best light possible.
• Are tests biased towards certain cultures?
Social desirability response set
Acquiescence response set

21. Reliability Validity 3 - 5yrs r = +0.5 12 - 14yrs r = +0.9 r = +0.7
IQ & academic achievement
r =
IQ & occupational status
r =
r = +0.3
IQ & income

22. Inheritance of Intelligence
Burt (1955)
80% hereditary
20% environmental
Kamin (1984)
0% hereditary
100% environmental
Identical twins r = 0.87
Fraternal twins r = 0.53
Separated identical twins r =
Siblings r = 0.5
Foster children reared together r = 0.2

23. Intelligence and Race
IQ scores between black and white Americans have shown differences of 15 points.
Jensen (1969) stressed biological differences
Environmentalists:
• tests were culturally biased
• environment may be different
• black people may experience prejudice and discrimination

24. Scarr and Weinberg (1976) adoption study - black children had IQ 25 points higher.
Tyler (1965)
IQ differences between black Americans in north and south.
Educational differences account for up to 24 points in IQ tests

25. Yerkes (1921)
Administered IQ tests to 125,000 young men in US army.
Goddard (1913)
Administered IQ test to immigrants to USA.

27. Items Relate to the Culture of the Edwards River Community
many
1. What comes next in the sequence: one, two, three, ___________ ?
2. As wallaby is to animal, so cigarette is to ________________ ?
(Choose from leaf, tree, tobacco, habit, lung cancer)
3. One of the following items may not be classified with salt water crocodile. Which one?
(marine turtle, frilled lizard, budgerigar, black snake)
4. Which items may be classified with sugar?
(honey, witchetty grub, flour, water-lilies)
5. We eat food and __________ water. Supply the missing verb.
tree
black snake
all of them
eat