Midterm 1

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Midterm 1

• Good job!
• Strict curve at this point
• 90 A 80 B 70 C lt 70 D
• Caveats
• 1 test can be dropped
• Doesnt consider extra credit
• Points, not grades, matter
• Advice
• Make sure to see what questions are being missed
• E.g., text vs. in class
• Adjust accordingly for next test

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Ch 6 Genetics and Personality

• 1. Introduction to
• 2. of Personality,
  Other Stuff
• 3. Environmental Effects on Personality

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Ch 6 Genetics and Personality

• Jim twins
• Jim Springer Jim Lewis!
• Both 180 pounds, 6 feet tall
• Both married twice
• First wives Linda!
• Second wives Betty!

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Ch 6 Genetics and Personality

• Jim twins
• Tastes
• Salem cigarettes
• Miller Lite
• Other
• How much do our genes contribute to
• Personality?
• Attitudes, preferences?

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Ch 6 Genetics and Personality

• Benefits
• 1.
• 2. Correcting
• 3.
• Issues
• 1. ? my genes, not
  me (psychopathy)
• 2. Eugenics designer babies, weeding out unfit

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Ch 6 Genetics and Personality

• Human genome
• Sequencing the entire genome
• First draft
• (what does this mean?)

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Ch 6 Genetics and Personality

• Human genome
• Most genes are identical
• Yet,
• Brown/blue eyes
• Unique genes must play a role

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Ch 6 Genetics and Personality

• Height
• Danny DeVito 5 feet
• Shaquille ONeal 7 feet
• What causes such dramatic diffs?
• Could be
• In fact
• Both true
• However,

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Ch 6 Genetics and Personality

• Heritability
• Of a
• Height
• Aggressiveness
• Neuroticism
• Due to

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Ch 6 Genetics and Personality

• Size
• .5
• .2
• Conventionally
• Envt
• E.g., 1 - .5 .5, suggesting .5 variance due to
  envt

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Ch 6 Genetics and Personality

• Misconceptions
• 1.
• Height is 90 heritable
• Michaels height is 90 heritable ?
• 2.
• Height in middle ages vs. today

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Ch 6 Genetics and Personality

• Heritabilities matter more for some stuff
• Height
• Weight
• Mate

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Ch 6 Genetics and Personality

• 1. Selective breeding
• 2. Family studies
• 3. Twin studies
• 4. Adoption studies

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Ch 6 Genetics and Personality

• Selective breeding
• Pit bulls - aggression
• Labradors - sociability
• Chesapeake Bay retriever - to fetch
• Selective breeding
• Other methods for humans

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Ch 6 Genetics and Personality

• Family studies
• Trait should be more similar
• For more similar family members
• Parents
• Each parent with a child
• Siblings
• Grandparents
• Potential problem
• Closer family
• Confound

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Ch 6 Genetics and Personality

• Twin studies
• Identical twins
• But zygote divides into
• Must be same sex
• Fraternal twins
• Gestated at same time
• Can be same or opposite sexes
• 2/3 of twins

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Ch 6 Genetics and Personality

• Heritability
• Height
• r .93 mz
• r .48 dz
• Plugging in values
• Heritability 2(.93 - .48)
• Height
• Rest of

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Ch 6 Genetics and Personality

• Adoption method
• Adoptive parents
• If envt has effect, children should be similar to
  adoptive parents
• Genetic parents
• If genes have effect, children should be similar
  to biological parents

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Ch 6 Genetics and Personality

• Heritability findings Personality traits
• E N
• 50 of E, N predicted by genes
• Typical finding
• Mz
• Dz
• Heritability 2(.51-.21)

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Ch 6 Genetics and Personality

• Heritability findings Temperament-like variables
• 1.
• Spinath et al. (2002) -
• Found heritability of movement
• 2. Other
• Emotionality, sociability, persistence
• Heritability

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Ch 6 Genetics and Personality

• Heritability of personality, summary
• 1. Almost any trait .5
• Those that seem
• Those that seem
• 2. Genes major contributor
• To stability/lack of change for personality

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Ch 6 Genetics and Personality

• Pretty stable over time
• Especially for
• Is sexual orientation heritable?
• Conventional wisdom yes
• Early Bailey studies
• But these studies were criticized
• Small n

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Ch 6 Genetics and Personality

• Sexual orientation
• Bailey et al (2000)
• 92 exclusively heterosexual
• Heritability
• Significant, but much smaller than previously
  thought

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Ch 6 Genetics and Personality

• Drinking, smoking
• If mz twin smokes, 16x more likely to smoke
  oneself
• But heritabilities a bit inconsistent, .3-.5
• More heritable
• .5-.6

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Ch 6 Genetics and Personality

• Marriage
• Whether one marries or stays single
• Marital satisfaction

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Ch 6 Genetics and Personality

• Attitudes toward Sabbath observance
• Divine law
• Church authority
• Bible as truth
• Fundamentalism
• Interest in becoming religious figure (e.g.,
  priest)
• religiosity

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Ch 6 Genetics and Personality

• Plomin et al (1990)
• due to shared envt (e.g., presence
  of TV, TV-watching parents)

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Lykken Tellegen (1996)

• Predicting happiness
• Education
• SES
• Income
• Marital status
• Demographics

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Lykken Tellegen (1996)

• Genetic basis to happiness?
• DZ twins
• Rate happiness
• Age 20 age 30
• Stability of happiness
• Genetics of happiness
• of stable happiness due to genes

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Lykken Tellegen (1996)

• 1. The reported WB of ones identical twinis a
  far better predictor than ones own life
  circumstances
• 2. trying to be happier is like trying to be
  tallercounterproductive
• 3. individual differences in human happinessare
  primarily a matter of (genetic) chance

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Ch 6 Genetics and Personality

• Waller Shaver (1994)
• Eros love at first sight
• Ludus dont get to serious, just fun
• Storge value reliability in partners
• Pragma pragmatic, mate with similar other
• Mania love-sick (e.g., insomnia when in love)
• Agape selfless enjoy giving
• These styles
• Not
• Rare

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Ch 6 Genetics and Personality

• Heritability lt 1
• Suggests envt contribution
• But
• Actually three things
• 1.
• 2.
• 3.

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Ch 6 Genetics and Personality

• Same parents
• Same toys
• Same schools, neighborhoods
• E.g., different treatment from parents
• E.g., diff friends at school
• E.g., one at paint chips

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Ch 6 Genetics and Personality

• Shared vs. unshared which matters more?
• Shared
• Matters
• E.g.,
• Unshared
• Why? dont know
• Which influences? dont know

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Ch 6 Genetics and Personality

• Shared envt nothing?
• Except
• Religious beliefs
• Political orientation
• Health behaviors (like diet, exercise)

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Behavioral Genetics

• Parenting - not very relevant?
• Which sperm/egg combo was given
• Sorry, wrong sperm!

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Behavioral Genetics

• What about adopting children?
• No genes
• Shared doesnt matter much
• Adopted children
• What is the point of adoption then?

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Ch 6 Genetics and Personality

• Must recreate itself to focus on
• why are children in same family so diff from
  each other?