ABSTRACT
The search for a taxonomy of individual differences is an ancient one: Humans have continuously sought to make sense of the myriad characteristics they observe in others around them. Whereas Thurstone found the correct number of broad personality factors, his collection of 60 trait adjectives was too idiosyncratically assembled to have produced Big-Five structure. Instead, the honor of first discovery must be accorded to Donald Fiske's who analyzed a set of 22 variables developed by Cattell, and found five factors that replicated across samples of self-ratings, observer ratings, and peer ratings. Before 1950, then, at least two separate five-factor models of phenotypic personality traits had appeared in the scientific literature—both with roots in the lexicographic tradition, but each using a different set of trait-descriptive variables. By 1970, then, one might have assumed that the five-factor model had amassed more than enough evidence to ensure its viability as the taxonomic framework for phenotypic personality traits.
