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The Intelligence Gap between Black and White Survey Workers on the Prolific Platform

Emil O. W. Kirkegaard


Published: 2022/09/01


This brief report analyzes data from a series of studies carried out by Bates and Gignac (2022), collected from paid survey takers on the Prolific platform (total n = 3357). In this UK sample, Black-White gap sizes on cognitive tests were substantial with an overall effect size d of 0.99 standard deviations adjusted for unreliability (unadjusted means = 0.84 d). Testing for measurement invariance via differential item functioning found either no bias or bias of trivial magnitude. We conclude that the Black-White intelligence gap seen in Prolific workers is of similar magnitude to the gap seen elsewhere in America. Key Words: Black-White gap, Race, Intelligence, Cognitive ability, Differential item functioning, Measurement invariance, Test bias, Survey, Questionnaire, Prolific

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