On the nature of intraindividual personality variability: Reliability, validity, and associations with well-being.

Intraindividual personality variability is a construct that reflects the extent to which a person's self-reported personality changes over time or across social roles. Past studies have linked variability with important outcomes such as adjustment and well-being. However, existing variability measures conflate mean-level variance with true change over time, and thus these past findings are questionable. Three studies were conducted to examine the psychometric properties of existing variability indexes and to develop a new index that does not suffer from the problem of conflated variance. This new index is reliable and valid and can predict actual changes in self-reports over time. However, once mean-level variance is removed, intraindividual variability is no longer related to well-being.