Commenter Mikey Blayze wrote:

Hey Pumpkin? Are you 100% sure there is no secret super low IQ black under class? Because im here to tell you there is -.- You have obviously never seen just how degenerate the inner city is from first hand experience. I spent a great deal of my young adult hood traveling to the inner city from my suburban home, usually for excitement and easy women and I can tell you there is a large group of blacks that have IQ of 75 , possibly lower.The IQ of the homeless is 85. They form groups, a social heirarchy, and co-ordinate together to make what little money they can. I have seen this for myself. I swear on my life there are at least hundreds if not thousands of adult inner city black males that survive solely on robbery and theft and their females survive of the meager financial support from the male activities. Tell me Pumpkin, What would the IQ be of someone who could only think of theft or robbery to make money. Theres a large amount of blacks that get away with this behavior constantly because in the inner city theres little to no police enforcement. The inner city is essentialy a modern day African Savannah. Its called a concrete jungle for a reason. Please do more research on a plausible theory before dismissing it.

I do agree that there are subpopulations of U.S. blacks with IQs below 75.  For example scholar Arthur Jensen discovered an entire school district in rural Georgia where the average IQ of late adolescents was about 70.  The question was whether these secret subpopulations are large enough to drag the national black IQ average down to 78, instead of the mean of 85 that is typically reported.

One reason for my skepticism is that tests like the Wechsler scales attempt to get extremely representative samples.  For example, the 1995 U.S. census reported that 18% of college age blacks had less than a high school diploma (about one fifth); meanwhile 21%  of college age blacks  in the 1995 norming of the Wechsler adult IQ test also had less than a high school diploma (also about one fifth).  Such careful matching of demographic variables gives me confidence that Wechsler norms are valid.

On the other hand, there is enormous IQ variation even among people with the same education, and this is especially true of blacks, so just because the Wechsler scales fully sampled low education blacks, does not mean they fully sampled low IQ blacks.

Scholars Rushton and Jensen wrote:

It is widely known among test developers that although samples are carefully drawn to create a nationally representative sample for the entire population, they are not chosen to get an accurate estimate for subgroups such as Blacks. The most disadvantaged elements in poorer schools in inner cities are rarely, if ever, included.


Thus I decided to take Mikey Blayze’s advice and do more research.  Although there are probably few if any studies on the IQs of poor inner city blacks, I did find a paper on the prison population in the Southern United States.  The paper reported that the white prisoners averaged IQ 87.66 on the WAIS-R, while the black prisoners averaged 78.47.

However because the WAIS-R was normed in 1978 and the prisoners were apparently tested in 1987, we should probably deduct 2.7 points for inflated norms (the Flynn effect), which reduces the IQs to 84.96 and 75.77 respectively.

It should also be noted that WAIS-R IQs are reported with reference to the entire U.S. population, not just the white population, which averaged IQ 101.4  SD = 14.65 on U.S. norms.  Compared to the national white mean and SD, white prisoners were -1.12 SD and black prisoners were -1.75 SD, corresponding to IQs of 83 and 74 respectively, using white norms.  Since the black inner city tends to have very high incarceration rates, the IQ 74 of black prisoners might be representative of the black underclass.

This is a bit higher than the rural Georgia black teens who averaged IQ 70.  On the other hand, a study of almost all black homeless people in Milwaukee showed an average IQ of 80 (white norms).  Averaging black prisoners in the South (IQ 74) with mostly black homeless in Milwaukee (IQ 80) with black teens in rural Georgia (IQ 70) probably gives a reasonable estimate of the IQ of the black underclass, and that estimate is 75 (white norms).

If the black underclass average IQ 75, it makes sense that the average U.S. black is about IQ 85 (white norms) and that the Wechsler samples are probably correct despite probably not sampling inner city blacks.