Is it all in the GENES Discussion Pair and Share What is a personality characteristic talent or skill that runs in your family Who in your family has it Make a little family tree chart depicting it ID: 305913
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Slide1
Heritability
Is it all in the GENES?Slide2
Discussion – Pair and Share
What is a personality characteristic, talent, or skill that runs in your family?
Who in your family has it?
Make a little family tree chart depicting it
What is the likelihood that the trait is
genetically influenced? Why do you say so?What is the likelihood that the environment has more to do with the trait being in the family?Slide3
What is heritability?
Review…
An estimate of the proportion of the total variance in some trait that is attributable to genetic differences among individuals within a group.
In other words…when looking at a group, how much of a certain trait is genetic
(vs.
environmental)?Key points:1. Only applies to a group living in the same environment2. DOES NOT apply to individuals, only to variations within a group3. Even highly heritable traits can be modified by the environmentSlide4
How do we test heritability?
Twin Studies
Why?
Why identical vs. fraternal? What would each show us?
http://www.youtube.com/watch?v=Wd5Y3-F79LY
Adoption Studies?Why?Slide5
Is your I.Q. genetic?
Intelligence Quotient
For many years calculated as:
Mental age/chron. Age X 100.
Is this a good way?What about other ways of showing intelligence?
Biases?Twin studies results:Identical twins scores correlated more than fraternalAdoption Studies:Children correlated more with biological parents than adopted parents.Slide6
I.Q. tests as a way to further RACISM
HH Goddard’s tests on immigrants (middle 105)
The Bell Curve
Remember Phrenology?
Eugenics
applied science or the bio-social movement which advocates the use of practices aimed at improving the genetic composition of a populationReading from “Race” is a Four-Letter Word: the Genesis of the ConceptSlide7
Flaws in Heritability Estimates
Most groups compared to mainly white samples.
People as Tomato Plant metaphor:
(
pg 107!)Slide8
Genes and Personality
Heredity and Temperament
Temperament = how we typically respond to our environment
Jerome
Kagan did research on infant temperaments and how that would affect people later in life
20% all babies highly reactive (excitable/nervous)20% all babies highly NONreactive (laidback/curious)Other 60% are somewhere in betweenReactive children…mild stressors caused more action in the sympathetic nervous system, more norepinephrine (adrenaline) and cortisol (increases blood sugar)Slide9
Heredity and Personality Traits
Trait
habitual way of thinking, behaving, and feeling
Raymond B.
Cattell’s Factor Analysis studies supported the idea of the
BIG 51. Introversion vs. Extroversion2. Neuroticism/ negative emotionality3. Agreeableness4. Conscientiousness5. Openness to experienceSlide10
Final Thoughts
If many studies show a .5 correlation between a trait and genetic inheritance, that means the other .5 of our make-up is influenced by our environment.
Some studies my underestimate the impact of the environment
Even traits that are highly heritable are not rigidly fixed and can be modified by experience.Slide11
“The wave of acceptance of genetic influence on behavior is growing into a tidal wave that threatens to engulf the second message of this research: These same data provide the best available evidence for the importance of environmental influences” (
Plomin
, 1989).Slide12
Discussion Questions:
***Get into your Group Trip to the Australian Outback***
1
. Just because a behavior is universal doesn’t mean that there is necessarily a genetic basis for the behavior. Geneticist Richard
Lewontin point out that if 99% of Finnish
are Lutheran, it doesn’t mean that Finns have a gene for Lutheranism. What other behaviors are universal (or almost universal), but are unlikely to be genetically determined? Slide13
2. Suppose that scientists developed a genetic test that would tell prospective parents whether they were carriers of a gene that contributes to obesity. Should this test be routinely offered to couples? What about a test that could predict lower than average intelligence? More generally, what are the consequences to individuals and to society of genetic engineering? Slide14
3. Evolutionary theory argues that variability is important for the ultimate survival of a species. But some would use genetic engineering to reduce variability and eliminate undesirable characteristics. What might be the possible problems with this approach? Can you imagine a scenario in which a genetic “flaw” resulting in obesity, for example, might be adaptive? Slide15
4.
If a gene is found for a predisposition to antisocial behavior, should this finding change the way we deal with criminals? If so, how?