Intelligence ! Flashcards
BACKGROUND
What did Spearman find about intelligence
- g intelligece
general intelligence (g) is basis of human intelligence
there are more specific forms/areas of intelligence (s) eg. logic, maths
said half of intelligence is explained by the g factor, the rest due to motivation /environmental factors e.g.. supportive teacher
BACKGROUND
What did Horn and Cattell find about intelligence
- fluid & crystalised intelligence
there is no single form of intelligence (g)
there are two main forms
fluid intelligence = ability to reason/solve problems logically WITHOUT experience
crystalised intelligence = ability to acquire knowledge through learning and EXPERIENCE
fluid = not effected by education
crystalised = effected by education
Genes related to intelligence
- problem with twin studies (usefullness)
MZ twins have higher concordance rates than DZ twins for intelligence
suggesting IQ has a genetic basis
however, in twin studies its difficult to separate environmental influences from genetic ones as MZ treated more similarly
can be overcome by raising twins separately > unethical
BACKGROUND
What was Bouchard and McGue’s aim and sample
AIM - to see the extent genes play a role in intelligence
SAMPLE - 111 studies from across the world, 500 familial IQ correlations on over 100,000 pairs of relatives (twin/family studies)
BACKGROUND
What did Bouchard and McGue find
DZ twins it was +0.60
When MZ twins were raised apart , the concordance was +0.72
Shows MZ twins who shared 100% genes, despite growing apart with different environments/education,
were more similar than DZ twins in same enviro but share 50% if genes
therefore significant role of heritability in intelligence and smaller role for enviro
Brain Structure and Intelligence
- study (grey matter)
Study found higher amounts of both grey and white matter in the brain were correlated with higher IQ scores
Therefore amount of grey + white matter can measure intelligence
KEY RESEARCH - key terms
Genetic transmission
Cultural transmission
GENETIC TRANSMISSION
= transfer of genetic information from genes to another generation
CULTRUAL TRANSMISSION
= the way a group of people within a society or culture tend to learn and PASS ON information
KEY RESEARCH - key terms
Phenotypic assortment
Social homogamy
PHENOTYPIC ASSORTMENT
= people select mates with similar intelligence levels
SOCIAL HOMOGAMY
= we end up selecting mate with similar IQ as they are in same social circle
KEY RESEARCH - VAN LEEWEN
- aim
- research method (methodological issues)
AIM = to carry out twin study which consider overlooked assumptions in research
eg. parents have different levels of intelligence / plays no role in enviro they provide for children
to test whether phenotypic assortment or social homogamy affects variation in IQ scores
RESEARCH METHOD - correlational study
- twin family design - corelation of IQs of twins + siblings + parents
- looked at relationship between intelligence and biological/environmental factors
KEY RESEARCH
- sample of van leewen
twins recruited from the Netherlands Twin Registry at VU University in Amsterdam
Families with children with major medical history excluded
112 families, mean age of twins was 9
KEY RESEARCH
- procedure of van leewen
data collection took place on two separate days
cheek swabs were taken as DNA + collected at home from parents + children to determine if twins were MZ or DZ
children and adults visited university to be tested for IQ in separate rooms so fairer/no help
children’s intelligence was assessed using Raven’s standard progressive matrices
parents intelligence was assed using Raven’s advanced progressive matrices (more difficult)
Raven’s provided scores that indicate general intelligence (g) and measured fluid intelligence (ability to solve problems not based on prior knowledge)
In analysis two theoretical models was used, one assumed parents had similar intelligence because of
- phenotypic assortment
- social homogamy
KEY RESEARCH
- results of van leewen (5)
1) correlations between pairs of IQ scores were higher for MZ twins than other relationships
(2) high correlation between Raven IQ between parents (both had high or low scores)
> provide evidence for phenotypic assortment as individuals seek partners with similar IQ )
3) 67% heritability for IQ !!
4) 33% due to environmental factors !!
5) Children born with low IQ are more affected by environmental; factors !!!
KEY RESEARCH
- conclusions of van leewen
Genetic factors are main influence on IQ
Cultural transmission doesn’t have influence on IQ
Phenotypic assortment explains similarities between parents IQ
KEY RESEARCH
- sampling bias
only netherlands - ethnocentric
- western country so non-western countries have different intelligence
Ravens Progressive Matrices = culture-fair test
> results of IQ aren’t biased to one culture
Excluded families with medical history/special educational needs
> sampling bias
KEY RESEARCH
- reliability & validity
RELIABILITY
Standardised genetic testing techniques
- cheek swabs
- more replicable
Raven’s Progressive Matrices
-internal- consistency of measure within itself
-external - gives similar IQ at different occasions
VALIDITY
Statistical analysis to measure contribution of genes+enviro to heritability of IQ
> increases validity as includes enviro unlike other twin studies
Raven’s Progressive Matrices + g intelligence
> other tests are more multidimensional
> g not valid measure of intelligence
