The interplay of personality and functional health in old and very old age: Dynamic within-person interrelations across up to 13 years.

Conceptual and empirical work has long suggested that personality and health are closely intertwined later in life. Little is known, however, about the nature and direction of time-ordered associations between the 2 domains within-persons. We applied continuous time auto- and cross-effects models to up to 6 waves of 13-year longitudinal data from the Berlin Aging Study (N = 516, M = 84.92, SD = 8.66, age range 70 to 103) and examined time-ordered relations between personality traits (i.e., extraversion and neuroticism) and performance-based indicators of functional health (i.e., physical and sensory functioning) in late life. Consistent with proposals to distinguish the young-old (age 70 to 84) from the oldest-old (aged 85+) in later life, results suggest that predictive effects of neuroticism on functional health are stronger in younger as compared with older individuals. In contrast, health decrements precede and predict change in neuroticism in the oldest-old more strongly as compared with the young-old. In addition, we found that decreases in extraversion predict subsequent decreases in functional health and vice versa, with effects being equally pronounced among younger and older participants. Furthermore, by employing continuous time models we could demonstrate that the magnitude of these effects varies depending upon the time interval under consideration. These findings suggest that personality and functional health are closely intertwined in old and very old age, and that the nature of time-ordered associations differs between traits and age period. We discuss conceptual and practical implications. (PsycINFO Database Record (c) 2018 APA, all rights reserved).