Did the Jizya – the Islamic Tax on Non-Muslims –Cause Selection for Intelligence? The Case of the Copts of Sudan

Edward Dutton

Published: 2026/03/01

Abstract

Studies have found that Christian theological tenets and related practice have led to selection favouring increased intelligence, but this has merely been speculated on in relation to Islam. The jizya, the tax imposed on non-Muslims in pre-nineteenth century Muslim societies, may have selected for higher intelligence among non-Muslims such as the Copts because wealthier, and therefore likely more intelligent, Copts could afford to pay it. We hypothesise, therefore, that Sudanese Copts would have higher IQ than the general Sudanese population. To examine this hypothesis, we analyse a study in which the SPM+ was administered to a sample of 424 Coptic Sudanese children aged between 6 and 11 years. The results were compared with those from a sample of Sudanese children who had also been administered the SPM+, controlling for age. Using British norms, it was found that the IQ of the Copts was 88, while the IQ of the Sudanese was 78. The difference is consistent with our hypothesis.

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