Intelligence Testing

Question 1

What is Intelligence?

Answer 1

Is it problem-solving abilities and verbal abilities? or the
‘capacity to acquire and retain knowledge, and to understand concepts and relationships’ or
‘to judge well, to comprehend well, to reason well’ (Binet and Simon (1916)
Is it simply ‘what intelligence tests measure’ (Boring, 1923).

Difficult to agree on what constitutes intelligence. Abilities.

Question 2

The intelligence Quotient

Answer 2

Tests establish mental age (MA) by comparing an individual’s performance with the average of others of different ages. This is then related to chronological age (CA):-

IQ = 100 x MA/CA

Tests - for each age group - are designed to have mean of 100 and a standard deviation of 15 - so that 68% of all scores fall within 85 and 115.

Such ‘norms’ enable us to determine whether an individual score is above or below average and by how much.

Question 3

Z Score

Answer 3

More use now of standard scoring methodology. An original test score is known as the raw score, and this is standardised to what is known as a standard score (or z score).

	z = (raw score-mean score)  /  standard deviation

By its signifying the number of standard deviations from the mean (+ or -) the z score can be compared to the normal distribution (of the relevant population) to find out where the particular person is placed in relation to the population as a whole. A percentile score is derived from the z score.

Question 4

Galton (1884)

Answer 4

on ethnic diversity of psychological traits (cf. his half-cousin Darwin (1859) on the evolution of physical traits in his ‘Origin of Species’).

Question 5

Binet (1904)

Answer 5

to identify mentally retarded children at an early age to give them special education provision. Practical device aimed to discover handling of intellectual tasks, e.g. comprehension, memory, rather than specific knowledge.

Question 6

Terman (1916)

Answer 6

adapted the Stanford-Binet Test.

Question 7

Yerkes (WW1)

Answer 7

• US Army Tests on 1.75 million army recruits. White American adults had average mental age of 13. Different races and nations ‘graded’ on test scores. Some races/nations were graded ‘inherently inferior’ to others.

Question 8

Immigration Restriction Acts (1921, 1924)

Answer 8

Continued interest in eugenics (selective breeding) to reduce ‘crime, pauperism and (improve) industrial inefficiency’. Aimed for a ‘golden register’ of elite. Sterilisation of ‘imbeciles’.
However….
Validity - does the test measure what it claims to measure, i.e. innate intelligence. Concerns where test questions - and even test pictures - were based on American general knowledge. Tests were testing experience rather than innate ability.

Question 9

Stanford Binet Test (Terman & Merrill 1960)

Answer 9

until 1986, a single measure, but since then different measures of abstract/visual reasoning, quantitative reasoning, and short-term memory (digit repetition). Lots of verbal reasoning (proverb explanation, sentence construction, etc), though, which again measures experience (crystallised rather than fluid intelligence).

Question 10

Wechsler Scales (Wechsler, 1948, 1974)

Answer 10

include scales for adults (WAIS) and for children (WISC). Former has 11 scales divided into verbal and non-verbal items (‘performance scale’)

Question 11

Verbal

Answer 11

Information
Comprehension
Arithmetic
Similarities
Digit Span
Vocabulary

Question 12

Non Verbal

Answer 12

Digit Symbol
Picture Completion
Block Design
Picture Arrangement
Object Assembly

Question 13

Ravens Advanced Progressive Matrices (Raven 1965)

Answer 13

fluid ability only, but a little narrow - so used with the Mill-Hill Vocabulary Scale.