Variability in negative affect is an important feature of neuroticism above mean negative affect once measurement issues are accounted for

Neuroticism is an important predictor of well-being that is conceptualized by high levels of mean negative affect and negative affect variability. However, research has shown that negative affect variability only explained limited additional variance in neuroticism when the confound with mean negative affect was accounted for using a modified version of the standard deviation (SD), the relative standard deviation (RSD). Here, we (a) examined the suitability of the RSD as a variability measure, (b) introduced the number of negative affect episodes as an alternative measure of negative affect variability, and (c) investigated the relationship between neuroticism and negative affect variability, accounting for measurement error. Re-analyzing three experience sampling datasets (N = 430 participants), we found several issues with the RSD, which limits its use as a negative affect variability measure, and which were not found for the number of negative affect episodes measure. Moreover, only the SD and the number of negative affect episodes explained substantial variance in neuroticism above mean negative affect. Thus, neuroticism was associated with experiencing negative affect more strongly and more often in daily life, when measurement error was accounted for, which demonstrates the importance to model reliability and to correct accordingly.