race iq real iq (rounded) genetic iq (rounded) brain size genetic brain size
ashkenazim 108 110  110 1457
east asians 105 105  105  1416  1534
whites 99 100  100 1369  1487
arctic people 91  95  95  1443  1561
southeast asians 87  90  95  1332  1450
native americans 86 90  90  1366  1484
pacific islanders 85 90  90 1317  1435
dark caucasoids 84 85  90  1293  1411
congoids 67  75  85  1280  1398
australoids 62 65  70  1225  1343
capoids 54 60  70 1270  1388
pygmies 54 60  70 1085  1203

The above chart has six columns.  In the first column I list 13 human races.  In the second column I list the IQs assigned to each of these 13 races by scholar Richard Lynn, on a scale where the British white mean is set at 100 (SD = 15).  In the third column I list the “real IQ” of each of these races.  That is, the IQ score each would get on a tuly culture reduced test, not the pseudo culture reduced tests they were often given like the Raven Progressive Matrices.  Real IQs were estimated by averaging the reported IQs in column 2, with the genetic IQ is column 4.

Genetic IQ

The genetic IQs in column 4 were estimated by noting that black Americans score about 85 on IQ tests as adults (even when reared by upper class whites) yet black Africans score 67, even though the two groups should have the same genetic IQ.  Yes black Americans have some white admixture which should have raised their genetic IQ above black Africans’, but they are also descended from perhaps the least intelligent class of black Africans (slaves) which should lower their genetic IQ below the average black Africans’, so on balance they should have the same genetic IQ.

And yet black African school kids score 18 points lower than African Americans, suggesting the poverty, illiterate parents,  malnutrition and disease of sub-Saharan Africa is  holding them back.  Averaging the 2001 human development index (HDI) of Cameroon and Cote D’Ivoire together (see table 7 of this paper), I estimated that sub-Sahara had a 2001 HDI of 0.448, compared to 0.937 for the United States and this roughly explained why they scored 18 points lower than U.S. blacks. From here I came up with the following formula:

Genetic IQ = Reported IQ + [(0.937 – population HDI)/0.02716]

For races that live in economically advanced countries such as Ashkenazim, East Asians, and Whites, IQs were assumed to equal genetic IQ, but for races like Southeast Asians and Pacific Islanders, I estimated the 2001 HDI of the Southeast Asia region to be 0.751 (based on the Philippines) and the above formula was applied.  Similarly, for Dark Caucasoids, I assumed the Middle East had an HDI of 0.709 (the average of Saudi Arabia and Egypt).

Although Arctic Peoples, Native Americans, and Austalian aboriginals technically live in developed countries, they are often segredated on reservations, and have HDIs below their fellow citizens.  Arctic Peoples were assigned an HDI of 0.851 based on the reported value for Canadian indigenous peoples (again see table 7 of this paper).  Native Americans were assigned an HDI of 0.864 based on averaging the HDI of Canadian and U.S. indigenous peoples.  Australian aboriginals reportedly had an HDI of 0.724.

Capoids and Pygmies were assumed to have the same HDI as mainstream black Africans (Congoids).  Although this is probably false, the Capoids and Pygmies used in actual IQ studies were those who lived side by side with their Congoid cousins under illiterate conditions.  Their actual IQ scores were probably a lot lower than the 54 Lynn reported for them, but because they scored about 13 points lower than illiterate Congoids, and Congoid school kids scored 67, it was assumed that Capoid and Pygmy school kids would score 67 – 13 = 54 if they too were in school.  Since the IQ was calculated under the scenario of similar environments, the genetic IQ was calculated assuming the same HDI.

Brain Size

Row 5 gives brain sizes reported by Lynn with the exception of pygmies which was reported by scolars C.L. Smith and K.L. Beals.  However since Lynn cited Smith and Beals as his brain size source, the figure should fit right in.

Row 6 gives estimated genetic brain size for each of the 13 races.  Because craniometry became taboo after WWII, I assume most of the brain size data was obtained before the 1930s, and perhaps well before the 20th century.  However Lynn notes that in the 1930s, people in the developed World began growing taller because of better health/nutrition and that height gains were perfectly paralleled by brain size gains.  Since height among U.S. whites has increased by 1.3 Standard Deviations over the 20th century before plateauing in 2006, I assumed that prior to the 1930s, Whites, and by extension every other race, were also 1.3 SD below their genetic brain size, and so genetic brain size was estimated by adding 118 cc to the Smith and Beals numbers.

To my knowledge Smith and Beals did not give data on Ashkenazim brain size, but very old studies suggest they were 30 cc below the white mean, so their genetic brain size is assumed to also be 30 cc below the genetic white mean.  These old studies give very different white brain sizes from Smith and Beals, showing how sensitive cranial capacity measures are to methodology.

I calculated the line of best fit to estimate the genetic IQ of a population from its genetic brain size, where X is genetic brain size (genetic cranial capacity) and Y is genetic IQ.  Pygmies were excluded because their small bodies make their brains abnormally small, even relative to IQ:

newfit

Advertisements