ABSTRACT The Big Five have not only been identified in ratings of knowledgeable informants, but also in ratings of strangers, in co-occurrence likelihood ratings of traits, in semantic similarity ratings of trait pairs, and in prototypieality ratings of acts for traits. This article describes the shared and distinctive characteristics of correlations among trait ratings and implicit personality theory and reviews studies that compare the structure of memory-based ratings and of on-line behavior counts. Three hypotheses suggested in the literature to account for these correlations are delineated and discussed: an accurate reflection hypothesis, a distortion hypothesis, and an overlap hypothesis. It is concluded that the distortion hypothesis has been discredited and that an overlap model best accounts for the available evidence. This implies that traits are real and accurately perceived, provided that the judges have the necessary information.