Discrepancies among different versions of Factor V may be largely explained by differences in the personality definitions and the variable selections used in various national trait taxonomies. Like any other social category the fifth factor has fuzzy boundaries and its meaning depends on the number and prototypicality of the exemplars included in the category. Resulting from taxonomies of traits (Norman, 1967; Goldberg, 1990) or dispositions (Ostendorf, 1990) the Five-Factor Model is not intended to represent or capable of representing the structure of all individual differences (e.g. attitudes, physical characteristics). Clear Intellect and Imagination versions of Factor V have only resulted from taxonomies including abilities and talents in their trait definition. The meaning of at least three of the Big Five would probably change if values—which we view as action prescriptions or behavioural intentions—were regarded as dispositions. Intellect, Imagination, and Creativity are the most prototypical attributes belonging to the core of Factor V. Comparisons among the various personality definitions and the procedures currently used in trait taxonomic research are needed to examine their effects on the replicability and the meaning of Factor V.