intelligence: group differences Flashcards
(11 cards)
IQ and diff countries
East Asian countries score highest, then Western and countries from temperate climates, then countries from tropics, then sub-Saharan Africa
BUT estimates are fallible as it’s difficult to get country representative samples to take identical IQ tests
what is IQ
imperfect, quantitative estimate of intelligence
scientifically and politically controversial
stereotyping and prejudice in IQ
males/females
whites/blacks
english/irish people
individual-group confusions = hasty generalisation - one infers that what is true of one individual is true for the group they belong to
ecological fallacy = expecting what is true for the group is true for any individual
one correctly infers through:
comparisons on an individual-basis many times (lots of pieces of individual evidence) AND there being big group differences
overall sex differences in intelligence
study of sex differences in mental aptitudes dates back to mid-19th century - John Stuart Mill argued there’s no difference between men and women BUT charles darwin argued women were inferior by nature
Stanford-Binet test (revised in 1940s) = preliminary test gave higher average IQ for women due to greater emphasis on verbal ability - test modified for equal gender scores
Spearman and Cattell = no sex differences in gender intelligence
Court, Jensen and Mackintosh analysed research using Raven’s Progressive Matrices and/or Wechsler intelligence test for finding sex differences
BUT Irwing and Lynn did meta analysis - no differences up to 15 years but then 2 IQ point advantage to men in school, 3.5 advantage in college, and adult men score 5 IQ points more than women (effect size is very small ie d=0.3)
BUT some recent studies didn’t replicate this ie Illiescu et al 2016
Water-Level Test
men more likely to draw horizontally, women draw line parallel to direction water glass is tipped
horizontal = correct
made by Piaget who looked at how children’s ability to understand matured - differences in men and women in college studying liberal arts but not in architecture (sex difference can be erased through learning)
supports idea that men are better at tests of spatial ability (the ability to visualise spatial relationships and to mentally manipulate objects) than women
other dimensions of spatial ability are:
spatial visualisation = analysing spatial info (ie looking for “embedded figures”)
mental rotation = visualising objects from diff angles and diff positions
Voyer et al 1995:
Maeda and Yoon 2013’s meta-analysis showed some of the most consistent and reliable sex diff are found in mental rotation
what do women do better than men in
Voyer et al 1995 found certain specific cognitive abilities women are better at:
superior on tests of:
verbal abilities (spelling/speech production)
perceptual speed (rapidly identify matching items)
women also do better in school (largest diff in language courses, smallest for math courses - effect size = d=0.23)
biological explanations of sex differences in intelligence
hormonal regulation
brain organisation
Broca 1861 - 432 human brains examined - average weight of male brain was 1325 grams whilst females was 1144 grams
Haier et al = differences in white and grey matter between women and men - parts of brain correlated with intelligence differed for men and women - but sample size was small and unlikely to generalise
Ritchie et al = males had higher cortical and sub-cortical volumes, cortical surface areas, and white matter diffusion directionality
females had thicker cortices and higher white matter tract complexity
overlap between distributions for males and females, and sub-regional differences were smaller after accounting for global differences - women had more brain linked to higher cognition - males did a little better on IQ tests but not much
Eliot et al 2021 = only way sex brains differ is size
some tasks solved more efficiently if carried out in one hemisphere than both sides - Rilea et al found men rely on one hemisphere, women share more functions across both
reasons for men’s better spatial ability
testosterone linked to spatial ability - castrated rats dosed with testosterone do better in mazes, but effect is complex and depends on dose
evolutionary differences - men were hunters and had to engage in warfare, and had to move around a lot to follow their penchant to mate wisely with females, so had to develop better spatial skills
BUT there’s no reason for women to have not developed spatial abilities too, it isn’t deprivating
men have practiced spatial ability more
environmental explanations of sex diff in intelligence
culturally prevalent stereotypes set up expectations that bring about self-fulfilling prophecies
Jussim = expectation are often rooted in reality and self-fulfilling prophecies aren’t very powerful, but may be stronger in stigmatised groups
framing spatial tasks in ways that “suit” females improves their performance on them - spatial tasks made more social or people put into them, the gender difference disappeared
The Bell Curve
Herrnstein and Murray = The Bell Curve - accusations of authors being racist BUT they suggest differences are both genes and environment - six assumptions:
1-general intelligence factor, g, exists (which most leading researchers believe, especially in WAIS or Raven’s progressive matrices)
2-IQ tests measure what they should measure
3-IQ test roughly measure what people regard as intelligence
4- IQ scores are stable (as shown by Deary!!)
5-IQ scores aren’t biased towards diff groups (most leading researchers believe this)
6-IQ is substantially heritable more than 40% and less than 80% (flexible and agreeable range)
claims:
IQ is best predictor of college attendance, not social class or wealth
IQ predicts job performance better than CV, experience etc
low IQ is predictive of social problems ie living in poverty or prison or unemployment (better predictor than social class)
cognitive elite is emerging in US
suggests average white IQ is 100 and average black IQ is 85 (difference of one SD between)
east asians score higher on IQ tests than whites and hispanics score higher than blacks
average income in USA follows same distribution
recommendations:
stop immigration and welfare which creates conditions to reduce IQ
understand IQ cannot easily be raised
end affirmative action for failing students, and invest in gifted students instead
IQ predicts violent crime - left-wingers suggest discrimination means blacks have lower IQ so turn to crime whilst right-wingers say low IQ causes black ppl to commit more crime etc
findings concerning IQ and achievement are consistent with IQ being highly heritable and genetically rooted
counters to IQ racial differences being genetically rooted
average IQ is 80-85 in India and 70-85 in Africa but 95-100 in UK
percentage of those getting 5 GCSE above C+:
somalis (recent immigrants) did worse than white british
chinese score high like the IQ of those from china
igbo tribe from nigeria get the highest percentage but average IQ from africa is low - similar to indians
median income for whites is $60K
income for east asian immigrant groups exceeds this as IQ is higher, BUT at very top if indian immigrants yet IQ is comparatively low
