Age-neutrality of the NEO-PI-R: Potential Differential Item Functioning in Older Versus Younger Adults

Geriatric researchers and clinicians often have to deal with a lack of valid personality measures for older age groups (e.g., Mroczek, Hurt, & Berman, 1999; Zweig 2008), which hampers a reliable assessment of personality in later life. An age-neutral measurement system is one of the basic conditions for an accurate personality assessment across the lifespan, both longitudinally and cross-sectionally. In the present study, we empirically investigate the age-neutrality of one of the most widely used personality measures (i.e., the NEO PI-R (Costa & McCrae, 1992)), by examining potential Differential Item Functioning (DIF). Overall, results indicate that the vast majority (92.9?% at domain-level and 95?% at facet-level) of the NEO PI-R items was similarly endorsed by younger and older age groups with the same position on the personality trait of interest, corroborating the NEO PI-R??s age neutrality. However, Differential Test Functioning (DTF) analyses revealed large DTF for Extraversion, and facet A6 (Tender-Mindedness). Results are discussed in terms of their implications for using the current format of the NEO PI-R in older aged samples.