Principles of Behavioral Genetics 2: Twins, heriability, and whole genomes Flashcards
Wright, Cesarini, KendlerOPT
____ twins hold the same genome, so we can look at twins who are ____ looks at how the human ____ affects behavior
identical; adopted; environment
____ twins are derived from the same egg and sperm, whereas ____ twins are derived from different eggs fertilized by different sperm, which makes their genetic composition like cousins
identical; fraternal
Adoption is an experiment of ____, where twins with same/similar genetic composition are reared in different environments
nurture
What are genetic relatives and environmental relatives?
Genetic relatives: relatives in one biological family
Environmental relatives: non-siblings reared together – different genes but same family environment
Caveats of twin studies: Twins may be more dissimilar ____ which leads to different birth weights, and they tend to have ____ birthweight and more often be premature. Also, how heritable a trait is may depend on the ____
prenatally; lower; environment
“Laws” of behavioral genetics (Eric Turkheimer): All normal human behavioral traits are ____, the effect of share family environment is ____ than effects of genes, and there is a ____ effect of “non-shared environment”
heritable; smaller; large
Wright article on Twins
Both Amy and Beth were ____ to families in the same ____ and had ____ siblings. The families both had some tension in them too
adopted; culture/state; older
Wright article on Twins
How were Amy and Beth treated differently in their households?
Amy was viewed as a failure and rejected child whereas her brother was the “golden child”; Beth was welcomed, and her brother was the “problem child”
Wright article on Twins
Apart from the genetic similarities and the adopted status, what might explain the similarities observed between Beth and Amy?
Shared non-family environment (culture, country, city); shared in utero environment; being in foster care and knowledge of being adopted (not fitting into the family)
Wright article on Twins
Nature vs Nurture:
Liberal viewpoints adopt a ____ argument and believes public programs can help improve people’s welfare. Conservatives hold a ____ viewpoint and argues that government assistance will not actually help improve a person’s lot in life
“Nurture”; “Nature”
Major questions of the Cesarini paper (twin study done in US and Sweden about trust and trustworthiness)
What are the relative roles of genetics and environmental influence in cooperative behavior in humans?
What was the hypothesis being tested in the Cesarini paper?
Cooperativeness is partially genetic, and there will be a measurable effect of genetics on performance in the trust game
- Propose that trust is heritable with environmental influences
What were the major results from the Cesarini paper?
- In both populations, the ACE and AE models (both included ____ and ____ ____ components) were best, suggesting that the ____ component is more important than the ____ ____ component.
genetic; unshared environment; common environment
In figure 2 of the Cesarini paper (the triangle thing), all are strongly skewed towards ____ ____ axis, with a slight trend on the ____ axis
unshared environment; genetic
Main conclusions from the Cesarini paper
- Human cooperative behavior may be at least partially under ____ control. The role of ____ environment is small, and the role of the ____ environment is quite large
genetic; common; unshared
