LECTURE 3- INTELLIGENCE (history)

Question 1

Francais Galton

Answer 1

• Believed Higher intelligence is caused by superior qualities passed down by heredity (1869)
• His central hypothesis- there are ID in intelligence, it is possible to measure intelligence directly.
• How he measured intelligence: reaction time, keenness of sight and hearing, the ability to distinguish between colours.

Question 2

Alfred Binet

Answer 2

• First intelligence test – Binet-Simon scale (1905)- aims to identify children who might require special education
• The test involved 30 tasks related to everyday life.
• The test results would determine the child’s ‘mental age’

Question 3

William Stern

Answer 3

• In 1912, he developed the idea of IQ
• Mental age varied among children proportionally to their real age
• Ratio mental age= chronological age was constant
• IQ= mental age divided by chronological age times 100

Question 4

Spearman

Answer 4

• First to use factor analysis
• 1904-1921 found positive correlations between intelligence tests (one who does well on one intelligence test will perform well on a vary of cognitive ability tests)
• He called this positive correlation the ‘positive manifold’
• Based on his idea of positive manifold, he proposed general intelligence, known as ‘g’ – this is what he thought was underlying all positive correlations.
• His two-factor theory: ‘g’ and ‘s’
• ‘g’= mental energy that is required to perform well on intelligence tests of all types; a deeper fundamental mechanism
• ‘s’ is specific abilities- specific types of intelligence needed to perform well on each different task (vocab, mathematical, special intelligence are examples of ‘s’)
• This theory of intelligence led to development of more rigorous intelligence tests that could be sued across the population e.g. Wechsler tests by David Wechsler

Question 5

Wechsler

Answer 5

●The Wechsler Adult Intelligence Scale (WAIS) developedby David Wechsler in the early 1900s.

●Most widely used intelligence test today.

●Yields an overall intelligence score, along with separateindex scores for:
1) verbal comprehension
2) perceptual reasoning
3) working memory
4) processing speed

The Wechsler intelligence scales are not considered adequate measures of extremely high and low intelligence (IQ scores below 40 and above 160).

Question 6

Deviation IQ

Answer 6

 Wechsler tested large groups of people to identify norms across different age groups
 The focus was on comparing scores with others of a similar age
 19339- deviation IQ= actual test score divided by expected score for that age times 100
 The IQ scores were then transformed and standardised such that the mean is 100 and the standard deviation is 15