| | Wikipedia: =========== Estimates of the heritability of IQ
Various studies have found the heritability of IQ to be between 0.7 and 0.8 in adults and 0.45 in childhood in the United States.[6][16][17] It may seem reasonable to expect that genetic influences on traits like IQ should become less important as one gains experiences with age. However, that the opposite occurs is well documented. Heritability measures in infancy are as low as 0.2, around 0.4 in middle childhood, and as high as 0.8 in adulthood.[7][18] One proposed explanation is that people with different genes tend to seek out different environments that reinforce the effects of those genes.[6]
A 1994 review in Behavior Genetics based on identical/fraternal twin studies found that heritability is as high as 0.80 in general cognitive ability but it also varies based on the trait, with .60 for verbal tests, .50 for spatial and speed-of-processing tests, and only .40 for memory tests.[5]
In 2006, The New York Times Magazine listed about three quarters as a figure held by the majority of studies,[8] while a 2004 meta-analysis of reports in Current Directions in Psychological Science gave an overall estimate of around .85 for 18-year-olds and older.[7]
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US test scores Main article: Achievement gap in the United States
Rushton and Jensen (2005 and 2010) write that in the United States, self-identified blacks and whites have been the subjects of the greatest number of studies. They state that the black-white IQ difference is about 15 to 18 points or 1 to 1.1 standard deviations (SDs). 15% to 20% of the black IQ distribution exceeds the white median IQ, so many blacks obtain scores above the white average. The black-white IQ difference is largest on those tests that best represent the general intelligence factor g.[19][23] The 1996 APA report "Intelligence: Knowns and Unknowns* and the 1994 statement "Mainstream Science on Intelligence" gave more or less similar estimates.[4][64] Roth et al. (2001) in a review of the results of a total of 6,246,729 participants on other tests of cognitive ability or aptitude found a black-white gap of 1.1 SD. Consistent results were found for college and university application tests such as the Scholastic Aptitude Test (N = 2.4 million) and Graduate Record Examination (N = 2.3 million), as well as for tests of job applicants in corporate sections (N = 0.5 million) and in the military (N = 0.4 million).[65]
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Conclusions: Whether its cause is genetic, environmental, or self determination: current adult US blacks have a lower IQ than current whites (whites being higher by 1-1.1 standard deviations).
Talking about genetics, the heritability of IQ is between 0.7 and 0.8 in adults.
I'm not sure what that "heritability" means. Kinda tired right now and not interested in doing mathematics at the moment.
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