WEEK 4: Ch:10, 11 Flashcards
First Intelligence tool?
-By Binet (Simon-Binet test)
Spearman
-Came up with the g factor (general factor of mental ability) diverse tasks are positively correlated.
- Simple tasks are worse indicator of factor g
-Harder tasks are better indicator of factor g
-Reasoning tasks correlate higher with the g factor.
Raven
-Spearman’s student who developed a test called Raven’s matrices similar to tasks relations and correlations.
Group factors
- Spearman discovered similar tasks highly correlate to each other so in order to not to loose the g factor he proposed he proposed 4 additional small factors:
1-verbal
2-spatial
3-perceptual
4-memory abilites
Thurstone
He didn’t agree with Spearman and argued that mental ability can not be measured with only one task so he offered 7 primary areas:
1-verbal fluency
2-verbal comprehension
3- numerical facility
4-spatial visualisation
5-Memory
6-Perceptual speed
7- Reasoning
Result: he realised all these factors highly correlate with each other so he factor analysed and agree with the g factor.
Development and IQ level
- IQ level increases throughout childhood and adulthood and starts decreasing after old age.
- In general stays relatively stable
Deary: 500 Scottish LTA IQ study
-IQ stays stable after childhood
- difference between the age of 8 and 80 is 1SD deviation.
-Growth of mental ability is higher than the decline of cognitive ability
WAIS IQ TEST Developmental results:
1-Verbal ability/Arithmetic problem solving : middle age adults > young adults =elderly
2- Spatial ability/ Perceptual speed/memory: young adults> older adults> elderly
-Results are not certain due to age-cohort effect.
Is brain size related to IQ?
No, only the thickness of the cerebral cortex and brain damage are related to IQ.
Reaction time tasks
1-Simple RT task (one light)
2-Choice RT task (2 lights)
3-odd-man-out (multiple lights)
-Correlation between IQ is -0.3
Inspection time
time period of an individual requires to notice a stimuli.
-Find the shorter stick
-correlation is -.3
Other biological correlates to mental ability:
1-Nerve conduction velocity: the speed which central nervous system transmits the electric impulse
2-Brain Waves: changes in electrical potential due to a stimuli
3-Brain glucose metabolism: the rate at which the brain consumes glucose
Heredity-Environment Influence on IQ
Genome-Wide complex trait analysis
- asses the similarity of a trait (IQ) in two people and examine wether they share more genes than people who are less similar in this trait. (r=.25)
Womb environment influence on IQ
- Devlin found .2 correlation for fraternal twins and , .05 for non twin siblings.
-Jacobs found monozygotic twins have more similar IQ than dizygotic
-Womb environment plays a role in IQ development.
Nutrition effect on IQ
-Twins who have to share the nutrition in one womb have slightly less IQ than their non-twin siblings.
-Nutiriton is correlated to IQ
Birth order effect on IQ
Older siblings tend to have a slightly more IQ than younger siblings.
Evolutionary function of mental ability
- Mental differences might be due to genetic mutations
- Men tend to score higher in spatial abilities (hunting) women tend to score higher in perceptual speed and emory ( gathering )
IQ scores and life outcome correlations:
1- Correlates to academic achievement
2-Job performance (higher correlation with cognitively complex tasks)
3- Occupational status and income correlate but not very high because there is a third factor of the family’s socioeconomic situation.
Longevity-Health and IQ
-There is a correlation between in both sexes because people with higher IQ’s tend to make smarted decisions. (quitting smoking)
Criminality and IQ
-There is a correlation with criminality however it is proven that high IQ people also commit crime but they do it for a higher cost or benefit whereas low IQ people do it due to poor prospect of success.
Marriage and IQ
Spouses tend to have similar mental abilities in some areas. (strongly correlate in verbal ability , less in nonverbal reasoning)
Cattel’s Fluid and Crystallised Intelligence
-Crystallized intelligent in tasks that are more well-learned (algebra, history,geography)
-Fluid Intelligence ( abstract/novel thinking)
Flynn effect
People nowadays score 1SD higher than people in 50’s. But this is the case for fluid intelligence not for crystal. Cause nowadays new generations need novel thinking.
