Studies done with Ethiopian immigrant students coming from extraordinarily poor rural circumstances tested in Israel by different IQ tests had, in pre-intervention tests, demonstrated lower test scores than the Israeli norm. However, after a short but intensive teaching process the Ethiopian immigrant children performed at about the same level as the Israeli norm (Tzuriel & Kaufman, 1999; Kozulin, 1998).
Plenty of other similar studies to be found at that link, including potential cultural biases of IQ testing generally.
A study by Serpell (1979) highlighted this well. Zambian and English children were asked to reproduce patterns using three media alternatives (wire, clay, or pencil and paper). It was found that the Zambian children excelled in the wire medium with which they were most familiar, exceeding the English children in that task; while the English children were best with pencil and paper. Both groups were found to perform equally well with clay. Thus, children performed better with the materials that were more familiar to them from their own environments. A study by Carraher et al (1985) also demonstrated examples of this effect, this time in a group of Brazilian children. The study found that the same children who were able to do the mathematics needed to run their street businesses were often unable to do “the same” mathematics when presented in a more formal (grade schooling) context.
It's not scientific at all, just garbage. If humans were sorted into categories based on inter-group genetic differences (intergroup differences themselves representing
only about 15% compared to the 85% of variation found
within local groups) the resulting races wouldn't be 'black,' 'white' or anything like the term is usually used. If I read this study correctly (Tishkoff et al, The Genetic Structure and History of Africans and African Americans; Science 2009 -
pdf), there is as much genetic diversity within India as there is in Central Asia, the Middle East and Europe
combined (figure 3). More startlingly, there's
more genetic diversity within Africa than in the rest of the world combined.
In other words if we imagined there to be an indigenous Oceanic race and a native American race, in terms of actual genetic diversity we'd then need to say that there are 3-5 east Asian 'races,' 6-10 Indian 'races,' and over 30 African races. Obviously that is not the kind of "important biological classification" which self-proclaimed 'race realists' are interested in!
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