Past studies of socially desirable self-reports on the items of personality measures have found inconsistent effects of the response bias on the measures' predictive validities, with some studies reporting small effects and other studies reporting large effects. Using Monte Carlo methods, we evaluated various models of socially desirable responding by systematically adding predetermined amounts of the bias to the simulated personality trait scores of hypothetical test respondents before computing test–criterion validity correlations. Our study generally supported previous findings that have reported relatively minor decrements in criterion prediction, even with personality scores that were massively infused with desirability bias. Furthermore, the response bias failed to reveal itself as a statistical moderator of test validity or as a suppressor of validity. Large differences between some respondents' obtained test scores and their true trait scores, however, meant that the personality measure's construct validity would be severely compromised and, more specifically, that estimates of those individuals' criterion performance would be grossly in error. Our discussion focuses on reasons for the discrepant results reported in the literature pertaining to the effect of socially desirable responding on criterion validity. More important, we explain why the lack of effects of desirability bias on the usual indicators of validity, moderation, and suppression should not be surprising.(PsycINFO Database Record (c) 2016 APA, all rights reserved)