“…Regarding social interactions (e.g., Cunningham, 1988aCunningham, , 1988b, creativity (e.g., Hirt et al, 1996;Richards, 1994), and evaluations of strangers (e.g., Baron, 1987Baron, , 1993, it appears that positive mood inductions do not produce symmetrical effects. Experimental laboratory research-for example, on helping, creativity, and task performance-also often includes neutral mood conditions, which do not parallel the effects of happy mood (e.g., Berkowitz, 1987;Cunningham, 1988a;Estrada et al, 1994;Isen, 1970Isen, , 1993Isen et al, 1985;Rosenhan et al, 1974). As another example, some crosssectional and longitudinal studies show significant effects of positive affect, but not negative affect-for example, on mortality risk in the nun study (Danner et al, 2001), on likelihood of developing a cold (Cohen et al, 2003), or on organizational citizenship (Credé et al, 2005).…”