Race and intelligence

The race and intelligence debate is a controversial issue, where considerations on both the nature of race and the meaning and measurement of intelligence have the potential to pre-empt the entire debate, according to many scholars.^{[1][2][3][4][5][6]} Important related questions include whether intelligence can be accurately described by a single number, and whether the nature of intelligence is the same across cultures, as well as ambiguities in the use of "race" as it is commonly understood to classify humanity.
At the base of the debate is the observation that intelligence quotient (IQ) tests have demonstrated significant differences in the average scores of different population groups, particularly US Blacks and Whites (racially self-identified for the most part). No consensus exists regarding the meaning and/or relevance of these differences, and numerous interpretations have been proposed to clarify them. A particularly controversial facet of this debate is the relative degree to which the development of intelligence is affected by genetic factors on the one hand and environmental factors on the other.
Within individuals, some factors of intelligence are clearly affected by genetics. However, no set populations of humans have been found to have significant genetic differences that would affect the average group intelligence. Also part of the debate is whether measures such as IQ can meaningfully quantify such differences, and whether it would be beneficial or ethical to study differences if they did exist.^[6] Various explanations for racial group differences have been proposed, such as the effect of a population's health, differences in education quality, sub-conscious psychological factors, and institutional racial discrimination. While environmental differences could statistically account for differences in test scores, no specific environmental factor has been identified as a definitive cause, and no direct evidence exists for genetic factors.^[7]
Although research and debate on race and intelligence encompasses a variety of topics, the nature versus nurture question attracts the most public attention.