G

G = General Intelligence
(Spearman, 1904)

Thought to exist because one test could predict the performance on another. 

WAIS | X = verbal IQ X = performance IQ

G = Measured in 4 main domains:

• Verbal Comprehension (chrystallised IQ)
• Working Memory (fluid IQ)
• Perceptual Organisation (fluid IQ)
• Processing Speed (fluid IQ)

*Fluid and Chrystalised IQ = Cattell 

All aspects test for a wide range of mental tasks.

Good performance on one test predicted good performance on another.
- nothing but positive correlations were seen between performance levels (from tendencies)
- no performance costs 
- seems to be identifiable pools of mental ability (with strong correlations amongst them)
- about half of variability attributed to mental abilities

= This suggests for general intelligence (G)

However WAIS may be too abstract.

Main idea = Intelligence is a hierarchy 
(compromise between singular IQ theory and multiple IQ theory)

General = 'g' factor

Broad = fluid IQ, chrystallised IQ (verbal), memory, processing speed

Narrow = specific forms of cognitive ability (from the broad domains above)

Creativity is associated with intelligence
- however, tis weakly related to IQ 
- cannot be easily measured (but tis valued amongst society)

Dyslexics
- suffer on chrystalised IQ and vocab tasks

(1) Is there such a thing as 'general intelligence'?

(2) How useful is it to conceptualise intelligence as a single entity?

(3) Critically evaluate the evidence for general intelligence.