Saini ch. 9

India is divided up into quite separate communities: Castes

• very strong cultural presumption that who your parents are determines your life, you are born a certain way
• the base of this is religion, not biology
• this worked culturally because it reduced competition
  
• one of the strongest examples of people still believing that groups should be kept separate
• so a natural experiment in breeding groups with distinct skills
• but that assumes genetics determines everything

Is intelligence heritable?

• would you see differences based on genes if people were raised identically?
• but they aren't--eg. a black child adopted by a white family experiences racism in school
  
• North Koreans are shorter even though height is quite heritable because they don't get enough nutrition growing up
• if intelligence is genetic it is controlled by thousands of genes each of which may be more or less common in different populations, and we don't know the mechanism by which they act
• for disadvantaged people, research shows environment causes virtually all the variation in intelligence
•  for very advantaged people who have ideal environments, there may be genetic differences
• but IQ itself is not fixed in an individual or over time
• improvements in research have tended to reduce the percentage of intelligence that is genetic
  

• small groups who only marry each other have led to high rates of some genetic illnesses in some groups
• culture is so tight that characteristics seem genetic when they are not
• culture strengthens itself by metaphors that you are born that way
  
• a large study of affirmative action in India found no differences in performance in those hired in a quota (they were hired because they were a member of a disadvantaged caste even though their test scores were slightly lower)