Are fluctuations in personality states more than fluctuations in affect?

People fluctuate in their behavior as they go about their daily lives, but little is known about the processes underlying these fluctuations. In two ecological momentary assessment studies (Ns = 124, 415), we examined the extent to which negative and positive affect accounted for the within-person variance in Big Five states. Participants were prompted six times a day over six days (Study 1) or four times a day over two weeks (Study 2) to report their recent thoughts, feelings, and behaviors. Multilevel modeling results indicated that negative and positive affect account for most, but not all, of the within-person variance in personality states. Importantly, situation variables predicted variance in some personality states even after accounting for fluctuations in affect, indicating that fluctuations in personality states may be more than fluctuations in state affect.