Black and White Americans with the same formal level of education differ significantly in their cognitive abilities. Specifically, within any given level of formal education Whites consistently outperform Blacks. Moreover, this effect is so strong that Blacks often underperform Whites who have lower levels of formal education than they do.
Consider the following data from the General Social Survey. This public data is frequently used in social science research and contains a test of verbal intelligence as well as measurements of participant’s self-identified race and highest educational degree obtained. Verbal intelligence tests correlate at around .75 with full-scale IQ and so this data can also be taken as a fair measure of intelligence in general (Lynn, 1998). If we set the White mean score on this test to 100 and the standard deviation to 15, we can come up with an “IQ” style scale.
As can be seen, using this method Blacks with a graduate degree have a level of verbal intelligence indistinguishable from that of Whites with a junior college degree. Blacks with a four-year degree are roughly on par with Whites who never went to college at all.
This data is consistent with evidence from the National Adult Literacy Survey (NALS) which administered tests of cognitive ability to 26,000 US adults in 1992. These tests were designed to measure how well people could take information and use it in a way which would help them function in modern society. This notion of “adult literacy” was broken down into three components:
“Prose literacy — the knowledge and skills needed to understand and use information from texts that include editorials, news stories, poems, and fiction; for example, finding a piece of information in a newspaper article, interpreting instructions from a warranty, inferring a theme from a poem, or contrasting views expressed in an editorial.
Document literacy — the knowledge and skills required to locate and use information contained in materials that include job applications, payroll forms, transportation schedules, maps, tables, and graphs; for example, locating a particular intersection on a street map, using a schedule to choose the appropriate bus, or entering information on an application form.
Quantitative literacy — the knowledge and skills required to apply arithmetic operations, either alone or sequentially, using numbers embedded in printed materials; for example, balancing a checkbook, figuring out a tip, completing an order form, or determining the amount of interest from a loan advertisement.”
Below we can see the racial gap in each test by education level (measured in standard deviations) and the IQ gap that this difference implies if we set the White distribution to have a mean score of 100 and a standard deviation of 15.
In this data set, Blacks at every level of formal education score lower on adult literacy measures than do whites who score one rank lower than them on this measure of educational attainment.
It is noteworthy that the actual implied IQ of both Blacks and Whites varies more by education level in the NALS data than it does in the GSS data. This is for at least two reasons.
The first reason is that vocabulary tests are generally among the best single measures of general intelligence and so the GSS data is probably a better approximation of full-scale IQ than is the NALS data. The second reason is that the GSS data included samples ranging from 1974 to 2014 whereas the NALS data included only a sample from 1992. Because of this, the difference in score may reflect the societal push to get everyone into college and thereby lessen educational attainment’s ability to predict individual differences.
It is also interesting to note that, with the exception of people with graduate degrees, the NALS data shows a larger racial gap at each level of education than does the GSS data even though the NALS literacy tests would likely appear more “culturally biased” to most people than the GSS verbal test.
The fact that Blacks at a given level of education have cognitive abilities equal to that of Whites at lower levels of education is probably explained by a few mechanisms.
First, there is well documented anti-White and pro-Black bias in the admission criteria of universities and medical schools. Blacks are allowed into universities with far lower test scores than what Whites would need in order to gain entry to these same schools. This necessarily has the effect of lowering the mean Black IQ, relative to Whites, at any given level of education.
Secondly, these differences may reflect cultural disparities in how Whites and Blacks view post-secondary education. Today, in spite of their relatively low test scores, Black recent high school graduates are more likely than White recent high school graduates to enter (though not to complete) college. To some degree, this is because of the previously referenced discrimination present in university admissions. However, it may also reflect the fact that Black parents are almost twice as likely as White parents to say that it is very important to them that their child gets a college degree.
Because of this, in conjunction with the relative lack of high IQ Black people in general, the idea that one should go to college regardless of their cognitive ability may be more common among Blacks than among Whites. Or that blacks are less likely to believe there even exists such a thing as “cognitive ability” and that only racists think in such terms.
A third relevant factor is that within any given level of formal education Whites may be going to harder schools than Blacks. This no doubt contributes to the fact that Whites have higher IQs than Blacks within the same level of education. However, it seems implausible that this can explain, for instance, why Black’s with graduate degrees scored lower than Whites with 2-year degrees in the GSS data. The graduate schools that Blacks go to cannot possibly be easier than junior colleges that Whites go to.
Socially, this finding is important because it implies that we cannot assume that Blacks and Whites with similar educational credentials will have equal cognitive abilities. Though most people are unfamiliar with the relevant data, many may have an intuitive grasp of this fact – an implicit skepticism of the Black woman with a Masters degree.
If so, this invalidates studies which attempt to measure discrimination against Blacks by showing that Whites are favored over Blacks for jobs even when they have equivalent or even lesser credentials. As we have seen, in education, Whites with lesser credentials normally have greater cognitive ability and functional literacy than Blacks with greater credentials, and so there is a rational, non-hateful, reason to prefer White applicants over Blacks even after matching their credentials.