This document is a book review of "Bias in Mental Testing" by Arthur R. Jensen. Jensen discusses intelligence as a phenotypic construct. The problem of ethnic differences in phenotypic intelligence is emotionally charged, which makes rational consideration of the issues difficult. The reviewer disagrees with the author's predisposition to propose and stress genetic explanations for test bias, to the exclusion of other explanations, and disagrees with his account of the various tests of the Spearman hypothesis. The reviewer also disagrees with Jensen's test theory discussion and cites several statistical errors in the book. Jensen's use of first principal component and first principal factor without discrimination as an operational definition of the general factor is questioned. Despite the criticisms, the reviewer believes that the data presented are generally sound and that those that bear on test bias cannot easily be dismissed. (DWH)