Group Differences

Group Differences

1. Race

   • No clear biological categories of humans
   • Bell Curve
     • Hernstein & Murray (1994)
     • Assumptions
       • 1. General intelligence factor 2. IQ predicts intelligence well 3. IQ measures everyday "intelligence" 4. IQ tests are unbiased 5. IQ is stable throughout life 6. 40-80% of intelligence is inherited
     • Criticisms
       • Of assumptions
         • 1. Cannot be a general intelligence factor if intelligence is hierarchical and intelligences are separate
         • 2. IQ cannot measure all types of intelligence therefore cannot be best predictor of intelligence. Different tests e.g. Ravens, SB measure different things
         • 3. People of different cultures, ages and disciplines have different interpretations of intelligence
         • 4. Theory of IQ is biased towards Western culture
         • 5. Evidence for fixed and malleable intelligence with environment 
         • 6. Inheritance explains differences within not between groups. Race is not a sensible distinction - colours are spread throughout the world and within race difference is 10x difference between
       • Statistical
         • Correlational and assumes intelligence and causal, ignoring SES and nutrition
         • Inconsistent research e.g. black children do better on Raven and choice RTs but these are not reported
         • Materials inappropriate e.g. Zulu children could not identify pictures of microwaves
       • Eugenics
         • Positive: encourage superior traits Negative: eliminate inferior traits Less intelligent people are making human race weak so must be eliminated
         • 1922 - sterilisation of disabled, dependent, blind etc 1941-43, 22,000 US killed
   • Race Differences
     • Asian Am - 107 White Am - 102 Immigrants - 95 Black Am - 87
     • Cognitive elite
       • Intelligence best predictor of college and job - so all intelligent people are in one place - class system will eventually be based on cognitive class
     • Social and economic factors
       • 1. Schooling - drop out = lower IQ 2. Mothers IQ - predicts motor co-ordination and cognitive developments 3. Family - nuclear families = higher IQ 4. Crime - criminals have 8 fewer IQ points 5. Welfare - IQ predicts first use of welfare  6. Unemployment - IQ predicts long term unemp. in men
     • Causal chain
       • Different environmental pressures have led to different selective pressures -Hot climate - dark skin and procreation to keep DNA alive -Cold climate - light skin and problem solving to adapt to cold e.g. get shelter
       • Recall: Sternberg's triarchic theory with practical and creative elements - when Oklahoma state introduced these abilities to admissions ethnic diversity increased
   • Social policy
     • -Education and nutrition interventions to increase intelligence unsuccessful because of heritability -Trying to increase had decreased intelligence in education because they are not able to fulfil potential
     • Correct comparison
       • - Matched on current or best conditions for either group  - Best conditions for each group
     • Resolution
       • -Beliefs about social justice have an influence e.g. that a standard classroom is "good enough" - Experimental difficulties - cannot leave education to chance like medical trials so we can only test interventions that we already know will work

2. Sex

   • Biological construct - social construst of gender determined by chromosomes. Some atypicalities dissociate chromosomal and hormonal sex
   • General differences
     • - No IQ difference - No Raven's difference - No difference up to 15 but gradual increase in M
   • Specific differences
     • Verbal
       • - Widespread belief that F> M not found - Primarily test of vocab which is only one factor of intelligence and does not correspond to F abilities - Adolescent girls do better but small effect sizes and effects get smaller
     • Spatial
       • Men consistently higher - largest difference for mental rotation
       • WHY?
         • 1. Gender role traits - more M less F traits do better 2. Stereotypes - activated -ve stereotype decreases F performance
       • Confidence
         • 1. +ve corr between confidence and accuracy - more likely to be right if you think you are 2. No sex difference if confidence  not considered by having to give answer 3. Performance changes according to feedback given and confidence increased or decreased
   • Biological explanationa
     • Brain size
       • - M brain size gets bigger proportionately in adulthood
     • Evolution
       • 1. Foraging - men need to gather food so spatial abilities negotiates environment 2. Polygamy - need to move around to find new partners 3. Warfare - need to negotiate to fight against enemies, know where enemy is etc.  
     • Brain functioning
       • - Men use RH in mental rotation - more efficient than F using both hems.
       • - M intelligence in white matter (info, processing) - F intelligence in gray matter (info transmission)
     • Testosterone
       • - Different route strategies for different hormones - Hormones affect perception  - T = faster responses and fewer errors
   • Environmental explanations
     • Outside education
       • - M (and monkeys) show preference for spatial toys from 9m e.g. building blocks, puzzles 
       • - Stereotypes - boys reject girls toys more than girls reject boys  - Modelling - want to be like same sex parent
     • Within education
       • Subject choice: F = language/arts/social M = maths/science/ engineering - other abilities do not get practised so worsen and do not get rewarded
       • Classroom interactions: - Self fulfilling prophecies - if told they are good at something they will perform/underperform -Stereotype threat - expected bad performance
     • Technology and SES
       • - If more activities involve spatial abilities then girls will fall behind more - No sex difference in low SES - less opportunity for spatial exploration e.g. computers, neighbourhood
   • Considerations
     • Stereotype emphasis
       • Overemphasise e.g. F verbal abilities Underemphasise Accurate e.g. M superior maths
     • Context
       • Assumption of size of difference may be wrong -Between M/F 5-10 IQ -Within M/F 70 IQ