Week 1 - Nature/nurture; genetics vs. experience Flashcards
What does formulating the question in terms of either/or do?
Not much; too simplistic and does not reflect reality…..breast feeding and IQ; maze bright and dull rats reared in impoverished and enriched environments; head start…
However, nature/nurture does make sense, when?
To ask what portion of the difference between individuals on a certain trait is due to genetics vs experience
To study the contribution of genetics to the differences between individuals, individuals with varying degrees of genetic similarity are s…
- Twin studies
a. Identical vs. fraternal
b. Raised together vs. adopted
c. Concordant vs. discordant for the trait of interest - Minnesota twin study
- I.Q. correlated .80 for identical twins raised together and .75 for those raised apart
- Schizophrenia 4 times higher in mono twins than di twins
- These results indicate that differences between individuals’ I.Q. and expression of schizophrenia has a genetic influence
What is the Heritability estimate
The estimate of the proportion of variability occurring in a particular trait in a particular study that resulted from the genetic variation in that study (.7 for IQ in the twin studies
What does the heritability estimate tell us?
a. tells us about the contribution of genetic differences to phenotypic differences among subjects – i.e. in the population
b. h.e. says nothing about the relative contribution of genetics and experience to the development of an individual
Interactive influences of genes and environment
-Environmental events directly influence transcription factors that control enhancer genes and determine if structural genes are expressed (twins raised apart, but grew up sim. SES)
The magnitude of a study’s heritability estimate depends on what?
The amount of genetic and environmental variation from which it was calculated and cannot be applied to other types of situations
