Intraindividual personality change: Situational influences, patterns of change, and frequency-based measurement

A large amount of research supports the idea that little change in personality occurs over time (e.g., Caspi & Roberts, 2001). However, changes in an individual’s personality across different situations, known as intraindividual, or within-person, variability, has not received nearly as much empirical attention, in part due to the difficulties inherent in measuring personality across situations. The present study evaluated a measure of within-person variability called frequency-based measurement by comparing it with situational personality expression. The study involved two phases: a one-time measure of trait personality using frequency-based measurement and a five day experience sampling (ESM) study involving repeated measures of state personality. Mean levels of the Big Five traits (i.e., extraversion, agreeableness, conscientiousness, neuroticism, and openness to experience), as measured by the frequency-based format, were significantly positively correlated with ESM measures of the traits, providing initial construct validity for this novel format. A major prediction in the study, that frequency-based variability in personality would be related to the state variability found in the ESM study, was not supported. However, variability in frequency-based measures of conscientiousness and neuroticism were related to both self-monitoring and self-concept clarity, and frequency-based variability in agreeableness was related to self-concept clarity. All of these relationships were small, indicating some divergent validity for frequency-based measurement. Finally, variability in any one of the Big Five traits was significantly positively correlated with variability in all of the other traits, in both measures (i.e., frequency-based measurement and ESM ratings). This provides support for traitedness (Baumeister & Tice, 1988), a theoretical approach to intraindividual variability that could help to explain why some individuals vary more than others depending on the situation. Overall, the present study found some support for the validity of frequency-based measurement as a method of evaluating intraindividual personality variability without the need for cost and time-intensive longitudinal studies