Intelligence

• Background 1


  Factor models
• Factor models 


  Spearman, Thurston, Cattell, Gardner
• Spearman


  Mental ability could be understood as a single factor, which could explain success across a range of tasks
• Thurston


  Verbal reasoning and verbal comprehension indicates intelligence
• Cattell


  Fluid intelligence (innate) and crystallised intelligence (learned)
• Gardner


  Multiple intelligences model; musical, interpersonal, spatial
• Background 2


  Biological factors
• Biological factors

  • Women are better at verbal reasoning
  • Men are better at mental rotation
  • Similar IQ
• Brain structure in men and women

  Men have more grey matter in the frontal and Paretial lobes, where women had more in the frontal and Brocus area
• What indicates that hormones effect gender differences in intelligence

  Female to male transexuals after given T had an increase in visual placing abilities and a decrease in verbal communication
• Background 3

  Genetic factors - Scarr + Weinberg
• Scarr + Weinberg


  Compared intellectual abilities in parents to biological and adopted children, found a stronger correlation with bio kids
• Evidence for genetic factors

  > Identical twins had a higher concordance rate when they were raised

  appart

  > Individuals with a thinner layer of grey matter in the left cerebral

  hemisphere performed less well in intellectual abilities
• Key research

  Van Leewen
• Van Leewen - Assortative mating

  Individuals with similar genes mate with one another
• Genotype environment interaction


  Specific environments activate specific genes
• Genotype environment correlation


  Parents pass on genes and environment
• Cultural transmission

  Particular culture passes on information
• Van Leewen - Sample

  > 112 twins

  > 48 Identical

  > 70 Fraternal

  > Split between male/female/opposite
• Van Leewen - Method

  Participants completed the cognitive (SPM) test in separate rooms.

  They were given instructions and no time limit.

  Test consisted of 60 problems divided into sets of 12.

  The test covered a range of cognitive abilities, such as identifying missing puzzle pieces.

  Adult completed more difficult versions (APM)

  Phenotypic assortment suggests assortative mating occurs because of choice, they are intellectual equals

  Social hegemony suggests people with similar IQ are clustered together (work environment)
• Van Leewen - results

  > Cultural transmission found to have no significant effect on genetic

  variance of IQ

  > High correlation for phenotypic assortment (0.33)

  > Environmental factors found to be more important in children with a

  genetic disposition for low IQ -> which suggests genotype

  environment interaction
• Applications

  > Raven's progressive matrices

  > RPM application

  > Flynn effect
• Raven's progressive matrices

  > Developed by John C Raven

  > Provides incomplete novel pictorial stimuli which participants have to

  make meaningful

  > P's have to select the missing aspect in a series of stimuli in order to complete a pattern (fluid intelligence)

  
• Usefulness of RPM

  > Useful with kids, as it is non verbal

  > Can be presented verbally, so useful for those with learning difficulties

  and research into developmental disorders (autism)

  > Military recruits; cultural neutrality

  > Standardised, so all tests are comparable
• Flynn effect


  Longitudinal study, found that IQ scores between generations has increased from 5 to 25 points

  
• Flynn study conclusions

  The test measures an ability related to intelligence (noticing patterns).

  This is because schools have changed their method of teaching.