The purpose of this study was to explore the relationships between extreme response style (ERS) in rating scale responses and the big five factors of personality. ERS is a tendency to select extreme rating alternatives frequently, regardless of specific item contents. Japanese versions of Perceptual Reaction Test (PRT) and word Reaction Test (WRT) were used as ERS scales. Correlational analysis of data from three samples, 534 undergraduates in total, showed that ERS correlated positively with playfulness of Tsuji et a1.'s Five-Factor Personality Questionnaire (FFPQ, 1998), and openness of NEO-PI-R (Shimonaka et al., 1999). The playfulness and openness scores had such a high correlation that they seemed to measure an identical trait. Although ERS also correlated with some facets of playfulness and openness, low alpha coefficients of some facet subscales would require further investigation of the relationships between ERS and the facets of the big five factors.
Key words: extreme response Style, openness, playfulness, FFPQ, NEO-PI-R