Lecture 2 - Nature and Nurture Flashcards
Nature and Nurture
- Nature - biological, natural, innate
- Nurture - learned behaviors, environmental factors
- developed by shakespeare
Nativism
All important knowledge, skills and abilities are built in
- extreme nature view
Empiricism
children are born as blank slates
- extreme nurture view
Most things in development are influenced by either nature or nurture? True or false?
False, most things are developed by both
What is an example of nature and nurture that we talked about during class?
- Siamese cats have diff. colors due to melanin pathway error. This error depends on the environment
- Obesity could be biological (leptin deficiency, FTO gene) or environmental
Leptin
- appetite hormone that regulates hunger, increased leptin causes fullness, decreased leptin causes hunger
FTO Gene
- impact appetite hormone differences in humans
- TT, AT, AA
- AA allele cause appetite hormone response to be delayed
- AA allele is inherited from parents, but what is done with the altered appetite depends on the individual
Behavioral Genetics
- role of genetics in behavior
- how variability results from combo of genetic and environmental factors
- behavioral traits are heritable to some degree
Polygenic
trait is due to two or more genes
Multifactorial
trait is due to genetics and the environment
Family Study
variable genetic relatedness, how correlated a trait is among individuals who vary in genetic relatedness
- greater genetic relatedness = similar outcomes
Monozygotic twins
identical, share 100% DNA
Dizygotic twins
fraternal, share 50% DNA
Adoption Study
- compare relatedness to biological family and adoptive family, infers genetic influences
- more similar to biological parents infers heavier influence of nature, more similar to adoptive parents infers heavier influence of nurture
Heritability
- what proportion of difference in a group is due to genes
- percentage of the role that nature plays
- stat. estimate of proportion of measure variability in a trait is attributable to genetic influences
When it is said that the heritability score for IQ is approx. 50%, what does this mean?
- 50% of variation in IQ is due to genetic diff btwn members of the population studied
Heritability estimates apply only to?
populations, not individuals
Allele
- two or more diff forms of a gene
- influence the same trait, but also contributes to outcome of the trait
Homozygous
two of the same alleles for a trait
- aa or AA
Heterozygous
two different alleles for a trait
- Aa
How does a shared and non-shared environment effect similarities btwn family members?
- shared - more similarities
- non-shared - increases diff among family members
Thin Fat Babies
- babies look thin, but body composition is adipose, high BMI
- discovered by Dr. Yajnik
- example of the thrifty gene hypothesis
Thrifty Gene Hypothesis
- baby’s body is adapting to conditions inside of mother, for ex; if mother is malnourished while pregnant, baby’s body will learn to hold onto fat and calories
- historically advantageous, but they became detrimental in the modern world
The Y-Y Pardox
- Yudkin and Yajnik
- Found that Yajnik has a higher BMI even though her and Yudkin weigh the same
- EX of thin-fat baby
Epigenetic change
- stable changes in gene expression mediated by the environment
- methylation
Methylation
- biochemical process that suppresses gene expression
- demethylation = gene turned on
- methylation = gene turned off
What was one of the examples of epigenetic inheritance we discussed in class?
- rat mothers/pups
- attention of mother stimulates glucocorticoid receptor gene in pups
- attentive mother = demethylation = active gene
- nonattentive = methylation is not gotten rid of = inactive gene
- dutch famine of 1944
