Individuals are considered to have stable personality traits. There is much research on how these traits affect many different outcomes, such as health, relationships, and finances. However, one long-term debate is whether people actually have any stable traits. This debate is due to the immense variability in how people act in different situations. That is, a individual’s behavior can be seen to be incredibly variable depending on the situation A colleague, Ellen Hamaker, writes about a very interesting approach to modeling the interaction of states and traits using structural equation modeling.

Another approach is taken by Walter Mischel and Yuichi Shoda. They investigate a single person with an intensive measurement approach (i.e., many measurements over time). Rather than averaging the person’s data into an average personality, they use the ‘noise’ that comes from the situation-individual interaction to create a behavior signature. That is, by determining how people act in different situations, a behavioral signature is created that is a stable pattern within that individual. Both of the above approaches are unique means to investigate the dynamics of personality. Both are mathematically intensive and have not yet been popularized as much as traditional personality models.

Below are some references to papers describing these techniques:

Hamaker, E. L., Nesselroade, J. R. & Molenaar, P. C. M. (in press). The integrated trait-state model. Journal of Research in Personality.

Hamaker, E. L., Dolan, C. V. & Molenaar, P. C. M. (2005). Statistical modeling of the individual: Rationale and application of multivariate stationary time series analysis. Multivariate Behavioral Research, 40(2), 207-233.

Mischel, W., Shoda, Y., & Mendoza-Denton, R. (2002). Situation-behavior profiles as a locus of consistency in personality. Current Directions in Psychological Science, 11, 50-54.

Shoda, Y. & LeeTiernan, S. (2002). What remains invariant?: Finding order within a person’s thoughts, feelings, and behaviors across situations. In D. Cervone & W. Mischel, Advances in Personality Science, 1, pp. 241-270.