Intelligence

Intelligence

1. Nurture

2. Nature

   • Family Resemblance Studies
     • Close Genetic Make up=Close IQ
     • Twins raised in different environments
       • eliminates nurture debate
       • adoption
     • Bouchard & McGue (1981)
       • Review of 111 worldwide studies
       • Mono Twins reared together= 0.86
       • Mono Twins reared apart= 0.72
         • More than Di twins reared together suggests genetic influences
       • Di Twins reared together= 0.60
       • Sibling reared together= 0.47
       • Siblings reared apart= 0.24
       • Cousins=0.15
       • Average Correlations of IQ
     • Bouchard & McGue (1990)
       • Minnesota Twin Study
         • 70% of IQ scores= Genetic Inheritance
   • Methodological Criticisms
     • Kamin (1977)
     • Difficult to control environmental influences
       • Adoption
         • Different environment not guaranteed
           • Similar family environments
         • Infants not separated from birth
           • Same womb experience
     • Self-selecting sampling techniques
       • Exaggeration of similarities
     • Different IQ tests
       • Can't compare results
   • Experimenter Bias
     • Validity
       • Cyril Burt...Rejected
     • Overly genetic interpretation of data
     • Neglect environmental influences
   • Selective Breeding
     • Thompson (1952)
       • "Maze-bright" rats
         • 6th generation= 80% fewer mistakes
       • "Maze-dull" rats
     • Henderson (1970)
       • Enriched environmental conditions
         • rats won't always improve
         • Some rats improved, suggests interaction between genetic abilities and environmental experience
       • obstacles to find food
     • Cannot selectively breed humans
       • Problems generalising results to humans