INTRODUCTION: Both in personality assessment and scientific research, self-report questionnaires are frequently used, yet the use of informant-report is increasing. The aim of this systematic review is to address the concordance and added value of informant- versus self-report in measuring personality pathology in (older) adults.
METHOD: A systematic search has been carried out for relevant literature published between 2000 and 2018, via the databases Scopus, PsychINFO and PubMED. Also the reference lists of included articles have been checked, resulting in an inclusion of 46 studies.
RESULTS: The concordance between informant- and self-report appears to be only moderate, but highest when the relationship is characterized by interpersonal intimacy (such as between partners). The concordance between informants is somewhat better than between informant- and self -reports. Informants have an added value over self-report in the context of externalizing personality traits and interpersonal functioning. In addition, they appear to be a better predictor for health, adaptability and professional functioning. Self-report on the other hand captures intrapsychic characteristics more thoroughly.
CONCLUSION: In personality assessment, informant- and self-reports could be complementary. However, empirical research among older adults is almost uncharted territory and deserves more attention.