The dynamic role of personality states in mediating the relationship between extraversion and positive affect.

The link between extraversion and positive affect (PA) has been one of the most important and robust findings in personality psychology, with a great deal of evidence that extraversion is related to both trait PA (Costa & McCrae, 1980; Lucas, Diener, Grob, Suh, & Shao, 2000; Watson & Clark, 1992), and state PA (Larsen & Ketelaar, 1991; Lucas & Baird, 2004; Lucas et al., 2000). What remains is the need to explain why extraverts are happier than introverts. The purpose of this paper is to test the hypothesis that part of the reason that extraverts are happier than introverts is that they enact more extraverted states, which lead directly to extraverts experiencing more PA states. Like affective states, personality states are characterized as having the same content as traits, but varying across short periods of time instead of being stable personality characteristics (Cattell, Cattell, & Rhymer, 1947; Fleeson, 2001; Nesselroade, 1988). Our hypothesis is grounded in the recent finding that state manifestations of extraversion consistently predict state PA (Fleeson, Malanos, & Achille, 2002; Heller, Komar, & Lee, 2007; McNiel & Fleeson, 2006; Schutte, Malouff, Segrera, Wolf, & Rodgers, 2003; Wolfe & Kasmer, 1988). Testing whether extraverts experience more PA than introverts because they actually enact more extraverted states in their daily lives is important for at least four reasons. First, the extraversion – PA relationship is a clear demonstration of the power of personality in affecting quality of life, yet until the mechanism is clear, the relationship remains an intriguing but unexplained phenomenon. The second reason is that it provides a test of a dynamic (e.g., process-oriented) versus a fixed account of traits. In contrast to fixed or temperamental explanations, which by definition treat the relationship between extraversion and PA as fairly immutable, our dynamic explanation suggests that that part of the reason extraverts are happier is because they act more extraverted, which brings about higher levels of PA. If the explanation has to do with what people do, rather than with what people have (Cantor, 1990), it suggests that models of traits ought to focus on mechanisms of state enactment as well as on structural features associated with traits. Third, the dynamic model raises the possibility that introverts, who already act extraverted on some occasions (Fleeson, 2001) and have the ability to act extraverted on demand (Fleeson et al., 2002; McNiel & Fleeson, 2006), might be able to increase their happiness by enacting more extraverted states in their daily lives. Fourth, these studies investigate whether states are meaningfully related to traits and whether aggregated states have the power to predict outcomes above and beyond the predictive ability of traits. Our mediation model tests both of these possibilities, as it provides another test of whether trait extraversion is manifested in daily extraverted behavior (see Fleeson & Gallagher, 2009), and it tests whether aggregates of extraverted states predict PA when accounting for the effects of trait extraversion.