The authors examined whether individuals can fake their responses to a personality inventory if instructed to do so. Between-subjects and within-subject designs were meta-analyzed separately. Across 51 studies, fakability did not vary by personality dimension; all the Big Five factors were equally fakable. Faking produced the largest distortions in social desirability scales. Instructions to fake good produced lowereffect sizes compared with instructions to fake bad. Comparing meta-analytic results from within-subjects and between-subjects designs, we conclude, based on statistical and methodological considerations, that within-subjects designs produce more accurate estimates. Between-subjects designs may distort estimates due to Subject x Treatment interactions and low statistical power.