Informant type is another possible moderator of trait stability. Roberts et al. (2008) hypothesized that increased personal awareness of one’s identity is responsible for increasing differential stability of personality traits with age. As one encounters more experiences where choices have to be made that lean toward higher extraversion (e.g., going to a party) compared to lower extraversion (e.g., staying at home), one’s identity becomes more strongly associated with these choices. This developmental model implies that self-reports of personality may be more likely to show evidence of increasing stability with age. In spite of this hypothesis, previous work has found little evidence that self- and peer-reports differ for behavioral genetic analyses (Riemann, Angleitner, & Strelau, 1997).
