Your SlideShare is downloading. ×
3 Feral
Upcoming SlideShare
Loading in...5

Thanks for flagging this SlideShare!

Oops! An error has occurred.


Introducing the official SlideShare app

Stunning, full-screen experience for iPhone and Android

Text the download link to your phone

Standard text messaging rates apply

3 Feral


Published on

Published in: Technology, Education

  • Be the first to comment

  • Be the first to like this

No Downloads
Total Views
On Slideshare
From Embeds
Number of Embeds
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

No notes for slide
  • Clearly, IQ is not the only psychological construct for which this debate applies, and instructors may wish to take a moment to name the other areas (i.e., personality, mental disorders, etc.) for which heritability is hotly debated.
  • Transcript

    • 1. Nature vs. Nurture in IQ
      • Are differences between people due to environmental or genetic differences?
      • Misunderstanding the question
        • “ Is a person’s intelligence due more to genes or to environment?”
        • no genes = no intelligence
        • both genes & intelligence crucial for any trait
    • 2. Nature vs. Nurture in IQ
      • Rectangle analogy
        • is a rectangle’s area due more to its width or its length?
        • are differences in area among rectangles due more to differences in their length or in their width?
      Group A Group B Length Width Length Width
    • 3. Heritability & Environmentality
      • Heritability
        • degree to which variation in trait stems from genetic, rather than environmental, differences among individuals
      • Environmentality
        • degree to which variation is due to environmental rather than genetic differences
    • 4. The Heritability Coefficient
      • Single number, ranging from 0 to 1.0
      • Represents amount of trait due to genetic differences
      • 0 means no variance due to genetics
      • 1 means all variance due to genetics
      • .30 means 30% is due to genetic differences, 70% due to environmental
    • 5. Twin Studies & Family Influence
      • If trait genetic:
        • closely related more similar than less closely related
      • Many close relatives share environments too
      • Types of studies to separate effects
        • monozygotic twins reared together
        • monozygotic twins reared apart
        • siblings/dizygotic reared together
        • siblings/dizygotic reared apart
        • adoptive siblings reared together
    • 6. Family Influence on IQ
      • Transient influence of family in which you are raised
        • adoptive siblings as children and adults
        • identical vs. fraternal twins reared together
      Fraternal twins Identical twins
    • 7. IQ Differences among Racial/Cultural Groups
      • Find differences among racial & cultural groups on IQ
        • American Blacks score about 15 points lower than Whites
      • WHY?
        • genetics?
          • Witty & Jenkins (1935)
          • No support for genetic differences
        • environment?
    • 8. IQ Differences among Racial/Cultural Groups
      • Each wheat field planted from same package of genetically diverse seeds
      • One field is quite fertile, the other is not
      • Within each field, differences due to genetics
      • Between each field, differences due to environment (fertility)
    • 9. Why differences between Blacks & Whites?
      • Social designation influences
        • autonomous minorities
          • deliberately separate themselves
        • immigrant minorities
          • came to country to better lives
          • see selves as better than those left behind
        • involuntary minorities
          • did not choose minority status
          • routinely judged as inferior by dominant majority
          • cross-cultural findings on IQ scores
    • 10. Historical increase in IQ
      • Improved performance on IQ tests over the years
      • Big increases in tests assessing fluid intelligence, smallest in factual knowledge
      • Increased schooling only accounts for small portion of this increase
      • Due to c hanges in the culture?
      Year IQ Scores
    • 11. Summary
      • Nature vs. nurture debate
        • heritability vs. environmentality
        • studies of twins & family influence
      • Racial & cultural differences in IQ
        • why we can’t interpret differences as due to genetics
        • what we can attribute the differences to
      • Historical increase in IQ scores