 To pare down his list, Goldberg asked study participants to rate from 1 (extremely inaccurate) to 9 (extremely accurate) how well a particular trait described themselves or others. Then using factor analysis, Goldberg could see which trait adjectives are closely related to each other, thereby making it reasonable to posit a “factor” or “latent variable” which could serve as a more fundamental underlying trait (Goldberg 1990, 1992, 1993 and Saucier and Goldberg 1996a; for an introduction to factor analysis in psychology, see Leary 2004: 187–192). Fearful and fretful, not surprisingly, were highly correlated, and were categorized under the heading of “neuroticism” in the Big Five.