The Human Varieties Global IQ Dataset

Richard Lynn’s international intelligence dataset has proved useful to many different researchers. (For example, in the year 2012 it was used by Hafer, Jones, Kalonda-Kanyama, Rindermann, Woodley.) His dataset has also been criticized over its accuracy and thoroughness. Although this data has been elaborated and corrected over time, some errors have been persistent. For example, IQ & the Wealth of Nations (2002) reported an IQ of 59 for Equatorial Guinea, based on a small study by Fernández-Ballesteros et al. (1997). Lynn subsequently emphasized this as the lowest national score in the dataset (Lynn & Vanhanen 2006, pp. 1-2), and this peculiarity, paired with a meager sample size (N=48), made it an easy target for critical reviewers already discomfited by the low values for Africa in general (Barnett & Williams 2004; Berhanu 2007). However, only veteran anti-hereditarian, Leon Kamin, bothered to eventually check the reference, and indeed, he found a major error: the sample was taken from a school for mentally handicapped children. But even Kamin’s reading was inadequate, and the full extent of the error wasn’t reported until Wicherts et al. (2010):

The average IQ of the people of Equatorial Guinea is based on a lengthy book chapter (Fernández-Ballesteros et al., 1997). Although this chapter reports research conducted among members of an illiterate tribe in Equatorial Guinea, the WISC-R was not administered to these Africans… The chapter clearly indicates that this study with 48 subjects was conducted in Spain. (p. 10, my emphasis)

Lynn finally published a retraction in 2010, 8 years after IQ & the Wealth of Nations, and 4 years after Kamin’s crtitique.

While some problems in the dataset have been corrected, new errors have also emerged over time, and not simply in added references. For example, the latest update—Intelligence: A Unifying Construct for the Social Sciences (2012)—includes several new references for Ireland, but also mistakenly omits a large, important study (Gill & Byrt 1973) cited in all previous versions of the dataset.

Lynn’s dataset has also been criticized for not including all relevant studies. In fact, I myself have been criticized for this: “We judge the [African IQ] reviews of Lynn (and Vanhanen) and Malloy to be unsystematic. These authors missed a large part of the literature on IQ testing in Africa… [and] failed to explicate their inclusion and exclusion criteria…” (Wicherts et al., 2010, p 11).

Wicherts is referring to the short editorial I wrote for Medical Hypotheses. However, I explicitly presented a “selected” sample of studies from the continent in support of Watson’s limited statement about African scores vis-a-vis Western scores. It certainly was not intended or presented as a list of all known studies, but as a reasonably general sampling of intelligence test scores from the region.

In fact, none of these reviews of African studies were as complete as they could have been. This is not surprising given the difficulty of locating or obtaining older studies, especially non-English language studies conducted in underdeveloped regions. I have, however, been tracking down world IQ studies for about 10 years now, and it’s probably safe to say that I have immediate hard drive access to more global intelligence test studies than any other person on earth. And with this website I now have a more transparent way of recording this data and a more immediate way of sharing it.

The upshot is a way to expand upon the labors of both Lynn and Wicherts. I’m going to try and use Human Varieties to tabulate a more thorough, immediate, and accurate dataset of international intelligence studies. A dataset that is participatory, updated frequently, and available for download.

The relevance or meaningfulness of this data is, of course, still an open question. But as long as researchers still find this kind of data useful, there is no harm in trying to improve it.

If you have any ideas for an improved global IQ dataset, please share them in the comments, or send me an email.



Barnett, S. M., & Williams, W. M. (2004). National intelligence and the emperor’s new clothes. Contemporary Psychology, 49, 389–396.

Berhanu, G. (2007). Black intellectual genocide: An essay review of IQ & the Wealth of Nations. Education Review, 10, 1-28.

Fernández-Ballesteros, R., Juan Espinosa, M., Colom, R., & Calero, M.D. (1997). Contextual and personal sources of individual differences in intelligence: Empirical results. In J.S. Carlson, J. Kingma, & W. Tomic (Eds.), Advances in cognition and educational practice: Reflections on the concept of intelligence, Vol. 4. (pp. 221–274). London, England: JAI Press Inc.

Gill, P., and Byrt, E. (1973). The Standardization of Raven’s Progressive Matrices and the Mill Hill Vocabulary Scale for Irish School Children Aged 6–12 Years. University College, Cork: MA Thesis.

Kamin, L.J. (2006). African IQ and mental retardation. South African Journal of Psychology, 36, 1-9.

Lynn, R. (2010). National IQs updated for 41 Nations. Mankind Quarterly, 50, 275-296.

Lynn, R., & Vanhanen, T. (2002). IQ & the wealth of nations. Westport, CT: Praeger.

Lynn, R., & Vanhanen, T. (2006). IQ & global inequality. Augusta, GA: Washington Summit Publishers.

Lynn, R., & Vanhanen, T. (2012). Intelligence: A Unifying Construct for the Social Sciences. London, UK: Ulster Institute for Social Research.

Malloy, J. (2008). James Watson tells the inconvenient truth: Faces the consequences. Medical Hypotheses, 70, 1081−1091.

Wicherts, J.M., Dolan, C.V., & van der Maas, H.L.J. (2010). A systematic literature review of the average IQ of sub-Saharan Africans. Intelligence, 38, 1-20.

Wicherts, J.M., Dolan, C.V., Carlson, J.S., & van der Maas, H.L.J. (2010). Raven’s test performance of Africans: Average performance, psychometric properties, and the Flynn Effect. Learning & Individual Differences, 20, 135-151.

1 Comment

  1. Ketrwa23

    “However, I explicitly presented a “selected” sample of studies from the continent in support of Watson’s limited statement about African scores vis-a-vis Western scores. It certainly was not intended or presented as a list of all known studies, but as a reasonably general sampling of intelligence test scores from the region.”

    I don’t think that’s what Wicherts et. al. said, because they emphasized you and others overlooked other studies and didn’t properly consider the validity of various studies for inclusion and exclusion. Your “reasonably general sampling” was apparently not so, which you admit.

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